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Sample records for ground-state energy bands

  1. Ground-state energies of simple metals

    NASA Technical Reports Server (NTRS)

    Hammerberg, J.; Ashcroft, N. W.

    1974-01-01

    A structural expansion for the static ground-state energy of a simple metal is derived. Two methods are presented, one an approach based on single-particle band structure which treats the electron gas as a nonlinear dielectric, the other a more general many-particle analysis using finite-temperature perturbation theory. The two methods are compared, and it is shown in detail how band-structure effects, Fermi-surface distortions, and chemical-potential shifts affect the total energy. These are of special interest in corrections to the total energy beyond third order in the electron-ion interaction and hence to systems where differences in energies for various crystal structures are exceptionally small. Preliminary calculations using these methods for the zero-temperature thermodynamic functions of atomic hydrogen are reported.

  2. A shock-tube determination of the CN ground state dissociation energy and electronic transition moments for the CN violet and red band systems

    NASA Technical Reports Server (NTRS)

    Arnold, J. O.; Nicholls, R. W.

    1973-01-01

    The CN ground state dissociation energy and the sum of squares of the electronic transition moments of the CN violet bands have been simultaneously determined from spectral emission measurements behind incident shock waves. The unshocked test gases were composed of various CO2-CO-N2-Ar mixtures, and the temperatures behind the incident shocks ranged from 3500 to 8000 K. The variation of the electronic transition moment with internuclear separation was found to be small for both the CN violet and red band systems.

  3. A shock-tube determination of the CN ground state dissociation energy and electronic transition moments for the CN violet and red band systems

    NASA Technical Reports Server (NTRS)

    Arnold, J. O.; Nicholls, R. W.

    1973-01-01

    The CN ground state dissociation energy and the sum of squares of the electronic transition moments of the CN violet bands have been simultaneously determined from spectral emission measurements behind incident shock waves. The unshocked test gases were composed of various CO2-CO-N2-Ar mixtures, and the temperatures behind the incident shocks ranged from 3500 to 8000 K. The variation of the electronic transition moment with internuclear separation was found to be small for both the CN violet and red band systems.

  4. Ground state energy of large polaron systems

    SciTech Connect

    Benguria, Rafael D.; Frank, Rupert L.; Lieb, Elliott H.

    2015-02-15

    The last unsolved problem about the many-polaron system, in the Pekar–Tomasevich approximation, is the case of bosons with the electron-electron Coulomb repulsion of strength exactly 1 (the “neutral case”). We prove that the ground state energy, for large N, goes exactly as −N{sup 7/5}, and we give upper and lower bounds on the asymptotic coefficient that agree to within a factor of 2{sup 2/5}.

  5. Ground state energy of N Frenkel excitons

    NASA Astrophysics Data System (ADS)

    Pogosov, W.; Combescot, M.

    2009-03-01

    By using the composite many-body theory for Frenkel excitons we have recently developed, we here derive the ground state energy of N Frenkel excitons in the Born approximation through the Hamiltonian mean value in a state made of N identical Q = 0 excitons. While this quantity reads as a density expansion in the case of Wannier excitons, due to many-body effects induced by fermion exchanges between N composite particles, we show that the Hamiltonian mean value for N Frenkel excitons only contains a first order term in density, just as for elementary bosons. Such a simple result comes from a subtle balance, difficult to guess a priori, between fermion exchanges for two or more Frenkel excitons appearing in Coulomb term and the ones appearing in the N exciton normalization factor - the cancellation being exact within terms in 1/Ns where Ns is the number of atomic sites in the sample. This result could make us naively believe that, due to the tight binding approximation on which Frenkel excitons are based, these excitons are just bare elementary bosons while their composite nature definitely appears at various stages in the precise calculation of the Hamiltonian mean value.

  6. Projected shell model study of ground state bands in 171-175Tm

    NASA Astrophysics Data System (ADS)

    Slathia, B.; Devi, R.; Khosa, S. K.

    2016-10-01

    The ground state bands of thulium isotopes with mass numbers (A), ranging from 171 to 175, have been investigated in the framework of the projected shell model. The theoretical results for the energy levels of ground state bands were found to be in reasonable agreement with the observed values. Predictably, E2 transition probabilities have got predicted vis-a-vis transitions with non-availability of experimental values. The E2 transition probability values have been observed to follow the same trend as seen in 171Tm.

  7. Centrifugal stretching along the ground state band of Hf168

    NASA Astrophysics Data System (ADS)

    Costin, A.; Reese, M.; Ai, H.; Casten, R. F.; Dusling, K.; Fitzpatrick, C. R.; Gürdal, G.; Heinz, A.; McCutchan, E. A.; Meyer, D. A.; Möller, O.; Petkov, P.; Pietralla, N.; Qian, J.; Rainovski, G.; Werner, V.

    2009-02-01

    The lifetimes of the Jπ=4+, 6+, 8+, and 10+ levels along the ground state band in Hf168 were measured by means of the recoil distance Doppler shift (RDDS) method using the New Yale Plunger Device (NYPD) and the SPEEDY detection array at Wright Nuclear Structure Laboratory of Yale University. Excited states in Hf168 were populated using the Sn124(Ti48,4n) fusion evaporation reaction. The new lifetime values are sufficiently precise to clearly prove the increase of quadrupole deformation as a function of angular momentum in the deformed nucleus Hf168. The data agree with the predictions from the geometrical confined β-soft (CBS) rotor model that involves centrifugal stretching in a soft potential.

  8. Ground state energy fluctuations in the nuclear shell model

    NASA Astrophysics Data System (ADS)

    Velázquez, Víctor; Hirsch, Jorge G.; Frank, Alejandro; Barea, José; Zuker, Andrés P.

    2005-05-01

    Statistical fluctuations of the nuclear ground state energies are estimated using shell model calculations in which particles in the valence shells interact through well-defined forces, and are coupled to an upper shell governed by random 2-body interactions. Induced ground-state energy fluctuations are found to be one order of magnitude smaller than those previously associated with chaotic components, in close agreement with independent perturbative estimates based on the spreading widths of excited states.

  9. Centrifugal stretching from lifetime measurements in the 170Hf ground state band

    NASA Astrophysics Data System (ADS)

    Smith, M. K.; Werner, V.; Terry, J. R.; Pietralla, N.; Petkov, P.; Berant, Z.; Casperson, R. J.; Heinz, A.; Henning, G.; Lüttke, R.; Qian, J.; Shoraka, B.; Rainovski, G.; Williams, E.; Winkler, R.

    2013-04-01

    Centrifugal stretching in the deformed rare-earth nucleus 170Hf is investigated using high-precision lifetime measurements, performed with the New Yale Plunger Device at Wright Nuclear Structure Laboratory, Yale University. Excited states were populated in the fusion-evaporation reaction 124Sn(50Ti,4n)170Hf at a beam energy of 195 MeV. Recoil distance doppler shift data were recorded for the ground state band through the J=16+ level. The measured B(E2) values and transition quadrupole moments improve on existing data and show increasing β deformation in the ground state band of 170Hf. The results are compared to descriptions by a rigid rotor and by the confined β-soft rotor model.

  10. Estimation of beryllium ground state energy by Monte Carlo simulation

    SciTech Connect

    Kabir, K. M. Ariful; Halder, Amal

    2015-05-15

    Quantum Monte Carlo method represent a powerful and broadly applicable computational tool for finding very accurate solution of the stationary Schrödinger equation for atoms, molecules, solids and a variety of model systems. Using variational Monte Carlo method we have calculated the ground state energy of the Beryllium atom. Our calculation are based on using a modified four parameters trial wave function which leads to good result comparing with the few parameters trial wave functions presented before. Based on random Numbers we can generate a large sample of electron locations to estimate the ground state energy of Beryllium. Our calculation gives good estimation for the ground state energy of the Beryllium atom comparing with the corresponding exact data.

  11. The Yukawa potential: ground state energy and critical screening

    NASA Astrophysics Data System (ADS)

    Edwards, James P.; Gerber, Urs; Schubert, Christian; Trejo, Maria A.; Weber, Axel

    2017-08-01

    We study the ground state energy and the critical screening parameter of the Yukawa potential in nonrelativistic quantum mechanics. After a short review of the existing literature on these quantities, we apply fifth-order perturbation theory to the calculation of the ground state energy, using the exact solutions of the Coulomb potential together with a cutoff on the principal number summations. We also perform a variational calculation of the ground state energy using a Coulomb-like radial wave function and the exact solution of the corresponding minimization condition. For not too large values of the screening parameter, close agreement is found between the perturbative and variational results. For the critical screening parameter, we devise a novel method that permits us to determine it to 10 digits. This is the most precise calculation of this quantity to date, and allows us to resolve some discrepancies between previous results.

  12. A Remark on the Ground State Energy of Bosonic Atoms

    NASA Astrophysics Data System (ADS)

    Hogreve, H.

    2011-08-01

    Monotonicity properties of the ground state energy of bosonic atoms as established in a recent paper by M.K.H. Kiessling [J. Stat. Phys. 139:1063 (2009)] are studied. Symmetry and scaling arguments lead to a more direct proof of a slightly stronger result of this monotonicity and the behavior of the ground state energy as a function of the number of bosonic electrons. Furthermore, invoking appropriate lower and upper bounds on two-electron systems, the stability of the bosonics He- ion is rigorously demonstrated.

  13. Mass coefficient and Grodzins relation for the ground-state band and {gamma} band

    SciTech Connect

    Jolos, R. V.; Brentano, P. von

    2006-12-15

    It is shown that the available experimental data on the energies of the first and the {gamma}-vibrational 2{sup +} states and the reduced E2 transition probabilities from these states to the ground state require for the explanation significantly different values of the mass coefficients for the rotational motion and {gamma}-vibrations.

  14. Electron scattering off the ground-state band and the. gamma. band in sup 150 Nd

    SciTech Connect

    Sandor, R.K.J.; Blok, H.P.; Garg, U.; Girod, M.; Harakeh, M.N.; de Jager, C.W.; de Vries, H. Service de Physique et Techniques Nucleaires, Commissariat a l'Energie Atomique, Bruyeres-le-Chatel, Boite Postale 12, F-91680 Bruyeres-le-Chatel, France Nationaal Instituut voor Kernfysica en Hoge-Energiefysica, sectie K , P.O. Box 4395, 1009AJ Amsterdam, The Netherlands Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556)

    1991-05-01

    Inelastic electron scattering to levels of the ground-state band and the {gamma} band in {sup 150}Nd was studied in a momentum transfer range of 0.5 to 2.8 fm{sup {minus}1}. The extracted transition charge densities were compared to microscopic Hartree-Fock-Boguliubov calculations. The overall agreement between the data and the calculations is good, indicating that the dynamic properties of the rotational collective degrees of freedom in statically deformed nuclei can be well described in this microscopic model.

  15. Available energy and ground states of collisionless plasmas

    NASA Astrophysics Data System (ADS)

    Helander, Per

    2017-08-01

    The energy budget of a collisionless plasma subject to electrostatic fluctuations is considered, and the excess of thermal energy over the minimum accessible to it under various constraints that limit the possible forms of plasma motion is calculated. This excess measures how much thermal energy is `available' for conversion into plasma instabilities, and therefore constitutes a nonlinear measure of plasma stability. A distribution function with zero available energy defines a `ground state' in the sense that its energy cannot decrease by any linear or nonlinear plasma motion. In a Vlasov plasma with small density and temperature fluctuations, the available energy is proportional to the mean square of these quantities, and exceeds the corresponding energy in ideal or resistive magnetohydrodynamics. If the first or second adiabatic invariant is conserved, ground states generally have inhomogeneous density and temperature. Magnetically confined plasmas are usually not in any ground state, but certain types of stellarator plasmas are so with respect to fluctuations that conserve both these adiabatic invariants, making the plasma linearly and nonlinearly stable to such fluctuations. Similar stability properties can also be enjoyed by plasmas confined by a dipole magnetic field.

  16. Ground State Energy of the Low Density Hubbard Model

    NASA Astrophysics Data System (ADS)

    Seiringer, Robert; Yin, Jun

    2008-06-01

    We derive a lower bound on the ground state energy of the Hubbard model for given value of the total spin. In combination with the upper bound derived previously by Giuliani (J. Math. Phys. 48:023302, [2007]), our result proves that in the low density limit the leading order correction compared to the ground state energy of a non-interacting lattice Fermi gas is given by 8 π a ϱ u ϱ d , where ϱ u( d) denotes the density of the spin-up (down) particles, and a is the scattering length of the contact interaction potential. This result extends previous work on the corresponding continuum model to the lattice case.

  17. Monte Carlo Ground State Energy for Trapped Boson Systems

    NASA Astrophysics Data System (ADS)

    Rudd, Ethan; Mehta, N. P.

    2012-06-01

    Diffusion Monte Carlo (DMC) and Green's Function Monte Carlo (GFMC) algorithms were implemented to obtain numerical approximations for the ground state energies of systems of bosons in a harmonic trap potential. Gaussian pairwise particle interactions of the form V0e^-|ri-rj|^2/r0^2 were implemented in the DMC code. These results were verified for small values of V0 via a first-order perturbation theory approximation for which the N-particle matrix element evaluated to N2 V0(1 + 1/r0^2)^3/2. By obtaining the scattering length from the 2-body potential in the perturbative regime (V0φ 1), ground state energy results were compared to modern renormalized models by P.R. Johnson et. al, New J. Phys. 11, 093022 (2009).

  18. Dissociation energy of the ground state of NaH

    NASA Astrophysics Data System (ADS)

    Huang, Hsien-Yu; Lu, Tsai-Lien; Whang, Thou-Jen; Chang, Yung-Yung; Tsai, Chin-Chun

    2010-07-01

    The dissociation energy of the ground state of NaH was determined by analyzing the observed near dissociation rovibrational levels. These levels were reached by stimulated emission pumping and fluorescence depletion spectroscopy. A total of 114 rovibrational levels in the ranges 9≤v″≤21 and 1≤J″≤14 were assigned to the X Σ1+ state of NaH. The highest vibrational level observed was only about 40 cm-1 from the dissociation limit in the ground state. One quasibound state, above the dissociation limit and confined by the centrifugal barrier, was observed. Determining the vibrational quantum number at dissociation vD from the highest four vibrational levels yielded the dissociation energy De=15 815±5 cm-1. Based on new observations and available data, a set of Dunham coefficients and the rotationless Rydberg-Klein-Rees curve were constructed. The effective potential curve and the quasibound states were discussed.

  19. Variable energy, high flux, ground-state atomic oxygen source

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Orient, Otto J. (Inventor)

    1987-01-01

    A variable energy, high flux atomic oxygen source is described which is comprised of a means for producing a high density beam of molecules which will emit O(-) ions when bombarded with electrons; a means of producing a high current stream of electrons at a low energy level passing through the high density beam of molecules to produce a combined stream of electrons and O(-) ions; means for accelerating the combined stream to a desired energy level; means for producing an intense magnetic field to confine the electrons and O(-) ions; means for directing a multiple pass laser beam through the combined stream to strip off the excess electrons from a plurality of the O(-) ions to produce ground-state O atoms within the combined stream; electrostatic deflection means for deflecting the path of the O(-) ions and the electrons in the combined stream; and, means for stopping the O(-) ions and the electrons and for allowing only the ground-state O atoms to continue as the source of the atoms of interest. The method and apparatus are also adaptable for producing other ground-state atoms and/or molecules.

  20. Ground state energies from converging and diverging power series expansions

    NASA Astrophysics Data System (ADS)

    Lisowski, C.; Norris, S.; Pelphrey, R.; Stefanovich, E.; Su, Q.; Grobe, R.

    2016-10-01

    It is often assumed that bound states of quantum mechanical systems are intrinsically non-perturbative in nature and therefore any power series expansion methods should be inapplicable to predict the energies for attractive potentials. However, if the spatial domain of the Schrödinger Hamiltonian for attractive one-dimensional potentials is confined to a finite length L, the usual Rayleigh-Schrödinger perturbation theory can converge rapidly and is perfectly accurate in the weak-binding region where the ground state's spatial extension is comparable to L. Once the binding strength is so strong that the ground state's extension is less than L, the power expansion becomes divergent, consistent with the expectation that bound states are non-perturbative. However, we propose a new truncated Borel-like summation technique that can recover the bound state energy from the diverging sum. We also show that perturbation theory becomes divergent in the vicinity of an avoided-level crossing. Here the same numerical summation technique can be applied to reproduce the energies from the diverging perturbative sums.

  1. a New Phenomenological Formula for Ground-State Binding Energies

    NASA Astrophysics Data System (ADS)

    Gangopadhyay, G.

    A phenomenological formula based on liquid drop model has been proposed for ground-state binding energies of nuclei. The effect due to bunching of single particle levels has been incorporated through a term resembling the one-body Hamiltonian. The effect of n-p interaction has been included through a function of valence nucleons. A total of 50 parameters has been used in the present calculation. The root mean square (r.m.s.) deviation for the binding energy values for 2140 nuclei comes out to be 0.376 MeV, and that for 1091 alpha decay energies is 0.284 MeV. The correspondence with the conventional liquid drop model is discussed.

  2. Ground-state and pairing-vibrational bands with equal quadrupole collectivity in 124Xe

    DOE PAGES

    Radich, A. J.; Garrett, P. E.; Allmond, J. M.; ...

    2015-04-01

    The nuclear structure of 124Xe has been investigated via measurements of the β+/EC decay of 124Cs with the 8π γ-ray spectrometer at the TRIUMF-ISAC facility. The data collected have enabled branching ratio measurements of weak, low-energy transitions from highly excited states, and the 2+ → 0+ in-band transitions have been observed. Combining these results with those from a previous Coulomb excitation study,more » $$B(E2; 2^+_3 → 0^+_2)$$ = 78(13) W.u. and $$B(E2; 2^+_4 → 0^+_3)$$ = 53(12) W.u. were determined. The $$0^+_3$$ state, in particular, is interpreted as the main fragment of the proton-pairing vibrational band identified in a previous 122Te(3He,n)124Xe measurement, and has quadrupole collectivity equal to, within uncertainty, that of the ground-state band.« less

  3. Graphene-like carbon nitride layers: stability, porosity, band gaps, and magnetic ground states

    NASA Astrophysics Data System (ADS)

    Chacham, Helio; da Silva-Araujo, Joice; Brito, Walber

    In the present work, we investigate the relative stability and electronic properties of carbon nitride (CxNy) graphene-like structures using a combination of a new bond-counting method and density-functional-theory (DFT) first-principles calculations. We obtain analytical and numerical results for the energetics and the morphology of graphene-like CxNy For instance, at high N concentrations, the bond-counting method allows us to search among millions of possible structures, and we find several ones with ab initio formation energies per N atom comparable to, or even smaller than, that of the isolated graphitic N impurity. Those structures are characterized by a variety of nanoporous graphene morphologies. The low-energy C-N structures also present a variety of band gaps, from zero to 1.6 eV, which can be tuned by stoichiometry and porosity. Several structures also present ferro- and antiferromagnetic ground states. We thank support from CNPq, CAPES, and FAPEMIG.

  4. Structural expansions for the ground state energy of a simple metal

    NASA Technical Reports Server (NTRS)

    Hammerberg, J.; Ashcroft, N. W.

    1973-01-01

    A structural expansion for the static ground state energy of a simple metal is derived. An approach based on single particle band structure which treats the electron gas as a non-linear dielectric is presented, along with a more general many particle analysis using finite temperature perturbation theory. The two methods are compared, and it is shown in detail how band-structure effects, Fermi surface distortions, and chemical potential shifts affect the total energy. These are of special interest in corrections to the total energy beyond third order in the electron ion interaction, and hence to systems where differences in energies for various crystal structures are exceptionally small. Preliminary calculations using these methods for the zero temperature thermodynamic functions of atomic hydrogen are reported.

  5. Centrifugal stretching along the ground state band of {sup 168}Hf

    SciTech Connect

    Costin, A.; Pietralla, N.; Reese, M.; Moeller, O.; Ai, H.; Casten, R. F.; Heinz, A.; McCutchan, E. A.; Meyer, D. A.; Qian, J.; Werner, V.; Dusling, K.; Fitzpatrick, C. R.; Guerdal, G.; Petkov, P.; Rainovski, G.

    2009-02-15

    The lifetimes of the J{sup {pi}}=4{sup +}, 6{sup +}, 8{sup +}, and 10{sup +} levels along the ground state band in {sup 168}Hf were measured by means of the recoil distance Doppler shift (RDDS) method using the New Yale Plunger Device (NYPD) and the SPEEDY detection array at Wright Nuclear Structure Laboratory of Yale University. Excited states in {sup 168}Hf were populated using the {sup 124}Sn({sup 48}Ti,4n) fusion evaporation reaction. The new lifetime values are sufficiently precise to clearly prove the increase of quadrupole deformation as a function of angular momentum in the deformed nucleus {sup 168}Hf. The data agree with the predictions from the geometrical confined {beta}-soft (CBS) rotor model that involves centrifugal stretching in a soft potential.

  6. Short-range interaction energy for ground state H2+

    NASA Astrophysics Data System (ADS)

    Battezzati, Michele; Magnasco, Valerio

    2006-12-01

    Two of the Hermitian eigenvalue equations resulting from the separation of the three-dimensional Schroedinger equation for H2+ in spheroidals are solved perturbatively for the ground state by expanding the action in positive powers of the internuclear distance R near the united atom He+. The dispersion relations between the separation constants A and Ee are seen to have rigorous analytic solutions, the third-order equation leading to an exact expansion for the inner determinantal equation up to R10. The explicit form for the expansion coefficients is determined up to n = 10, and is seen to contain up to the third power of (γ + ln 4R) logarithmic terms. Even if the general range of validity of the short-range Rn-expansion is expected to be smaller than the corresponding long-range R-n-expansion, it is important to stress that such higher expansion coefficients are calculated exactly for the first time. These formulae give extremely accurate numerical results up to R cong 0.3a0.

  7. Ground-state energies of the nonlinear sigma model and the Heisenberg spin chains

    NASA Technical Reports Server (NTRS)

    Zhang, Shoucheng; Schulz, H. J.; Ziman, Timothy

    1989-01-01

    A theorem on the O(3) nonlinear sigma model with the topological theta term is proved, which states that the ground-state energy at theta = pi is always higher than the ground-state energy at theta = 0, for the same value of the coupling constant g. Provided that the nonlinear sigma model gives the correct description for the Heisenberg spin chains in the large-s limit, this theorem makes a definite prediction relating the ground-state energies of the half-integer and the integer spin chains. The ground-state energies obtained from the exact Bethe ansatz solution for the spin-1/2 chain and the numerical diagonalization on the spin-1, spin-3/2, and spin-2 chains support this prediction.

  8. Ground-state energies of the nonlinear sigma model and the Heisenberg spin chains

    NASA Technical Reports Server (NTRS)

    Zhang, Shoucheng; Schulz, H. J.; Ziman, Timothy

    1989-01-01

    A theorem on the O(3) nonlinear sigma model with the topological theta term is proved, which states that the ground-state energy at theta = pi is always higher than the ground-state energy at theta = 0, for the same value of the coupling constant g. Provided that the nonlinear sigma model gives the correct description for the Heisenberg spin chains in the large-s limit, this theorem makes a definite prediction relating the ground-state energies of the half-integer and the integer spin chains. The ground-state energies obtained from the exact Bethe ansatz solution for the spin-1/2 chain and the numerical diagonalization on the spin-1, spin-3/2, and spin-2 chains support this prediction.

  9. A new accurate ground-state potential energy surface of ethylene and predictions for rotational and vibrational energy levels.

    PubMed

    Delahaye, Thibault; Nikitin, Andrei; Rey, Michaël; Szalay, Péter G; Tyuterev, Vladimir G

    2014-09-14

    In this paper we report a new ground state potential energy surface for ethylene (ethene) C2H4 obtained from extended ab initio calculations. The coupled-cluster approach with the perturbative inclusion of the connected triple excitations CCSD(T) and correlation consistent polarized valence basis set cc-pVQZ was employed for computations of electronic ground state energies. The fit of the surface included 82,542 nuclear configurations using sixth order expansion in curvilinear symmetry-adapted coordinates involving 2236 parameters. A good convergence for variationally computed vibrational levels of the C2H4 molecule was obtained with a RMS(Obs.-Calc.) deviation of 2.7 cm(-1) for fundamental bands centers and 5.9 cm(-1) for vibrational bands up to 7800 cm(-1). Large scale vibrational and rotational calculations for (12)C2H4, (13)C2H4, and (12)C2D4 isotopologues were performed using this new surface. Energy levels for J = 20 up to 6000 cm(-1) are in a good agreement with observations. This represents a considerable improvement with respect to available global predictions of vibrational levels of (13)C2H4 and (12)C2D4 and rovibrational levels of (12)C2H4.

  10. The H 2O ++ Ground State Potential Energy Surface

    NASA Astrophysics Data System (ADS)

    Bunker, P. R.; Bludsky, Ota; Jensen, Per; Wesolowski, S. S.; Van Huis, T. J.; Yamaguchi, Y.; Schaefer, H. F.

    1999-12-01

    At the correlation-consistent polarized-valence quadruple-zeta complete active space self-consistent field second-order configuration interaction level of ab initio theory (cc-pVQZ CASSCF-SOCI), we calculated 129 points on the ground electronic state potential energy surface of the water dication H2O++; this calculation includes the energy of X3Σ- OH+ at equilibrium and the energy of the triplet oxygen atom. We determined the parameters in an analytical function that represents this surface out to the (OH+ + H+) and (O + 2H+) dissociation limits, for bending angles from 70 to 180°. There is a metastable minimum in this surface, at an energy of 43 600 cm-1 above the H+ + OH+ dissociation energy, and the geometry at this minimum is linear (D∞h), with an OH bond length of 1.195 Å. On the path to dissociation to H+ + OH+, there is a saddle point at an energy of 530 cm-1 above the minimum, and the geometry at the saddle point is linear (C∞ Kv) with OH bond lengths of 1.121 and 1.489 Å. Using the stabilization method, we calculated the lowest resonance on this surface. Relative to the metastable local minimum on the potential energy surface, the position of the lowest resonance for H2O++, D2O++, and T2O++ is 1977(85), 1473(25), and 1249(10) cm-1, respectively, where the width of each resonance (in cm-1) is given in parentheses.

  11. Surface modification using low energy ground state ion beams

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)

    1990-01-01

    A method of effecting modifications at the surfaces of materials using low energy ion beams of known quantum state, purity, flux, and energy is presented. The ion beam is obtained by bombarding ion-generating molecules with electrons which are also at low energy. The electrons used to bombard the ion generating molecules are separated from the ions thus obtained and the ion beam is directed at the material surface to be modified. Depending on the type of ion generating molecules used, different ions can be obtained for different types of surface modifications such as oxidation and diamond film formation. One area of application is in the manufacture of semiconductor devices from semiconductor wafers.

  12. Ground-state and pairing-vibrational bands with equal quadrupole collectivity in 124Xe

    SciTech Connect

    Radich, A. J.; Garrett, P. E.; Allmond, J. M.; Andreoiu, C.; Ball, G. C.; Bianco, L.; Bildstein, V.; Chagnon-Lessard, S.; Cross, D. S.; Demand, G. A.; Diaz Varela, A.; Dunlop, R.; Finlay, P.; Garnsworthy, A. B.; Hackman, G.; Hadinia, B.; Jigmeddorj, B.; Laffoley, A. T.; Leach, K. G.; Michetti-Wilson, J.; Orce, J. N.; Rajabali, M. M.; Rand, E. T.; Starosta, K.; Sumithrarachchi, C. S.; Svensson, C. E.; Triambak, S.; Wang, Z. M.; Wood, J. L.; Wong, J.; Williams, S. J.; Yates, S. W.

    2015-04-01

    The nuclear structure of 124Xe has been investigated via measurements of the β+/EC decay of 124Cs with the 8π γ-ray spectrometer at the TRIUMF-ISAC facility. The data collected have enabled branching ratio measurements of weak, low-energy transitions from highly excited states, and the 2+ → 0+ in-band transitions have been observed. Combining these results with those from a previous Coulomb excitation study, $B(E2; 2^+_3 → 0^+_2)$ = 78(13) W.u. and $B(E2; 2^+_4 → 0^+_3)$ = 53(12) W.u. were determined. The $0^+_3$ state, in particular, is interpreted as the main fragment of the proton-pairing vibrational band identified in a previous 122Te(3He,n)124Xe measurement, and has quadrupole collectivity equal to, within uncertainty, that of the ground-state band.

  13. Ground state energies from converging and diverging power series expansions

    SciTech Connect

    Lisowski, C.; Norris, S.; Pelphrey, R.; Stefanovich, E. Su, Q.; Grobe, R.

    2016-10-15

    It is often assumed that bound states of quantum mechanical systems are intrinsically non-perturbative in nature and therefore any power series expansion methods should be inapplicable to predict the energies for attractive potentials. However, if the spatial domain of the Schrödinger Hamiltonian for attractive one-dimensional potentials is confined to a finite length L, the usual Rayleigh–Schrödinger perturbation theory can converge rapidly and is perfectly accurate in the weak-binding region where the ground state’s spatial extension is comparable to L. Once the binding strength is so strong that the ground state’s extension is less than L, the power expansion becomes divergent, consistent with the expectation that bound states are non-perturbative. However, we propose a new truncated Borel-like summation technique that can recover the bound state energy from the diverging sum. We also show that perturbation theory becomes divergent in the vicinity of an avoided-level crossing. Here the same numerical summation technique can be applied to reproduce the energies from the diverging perturbative sums.

  14. Van der Waals potential and vibrational energy levels of the ground state radon dimer

    NASA Astrophysics Data System (ADS)

    Sheng, Xiaowei; Qian, Shifeng; Hu, Fengfei

    2017-08-01

    In the present paper, the ground state van der Waals potential of the Radon dimer is described by the Tang-Toennies potential model, which requires five essential parameters. Among them, the two dispersion coefficients C6 and C8 are estimated from the well determined dispersion coefficients C6 and C8 of Xe2. C10 is estimated by using the approximation equation that C6C10/C82 has an average value of 1.221 for all the rare gas dimers. With these estimated dispersion coefficients and the well determined well depth De and Re the Born-Mayer parameters A and b are derived. Then the vibrational energy levels of the ground state radon dimer are calculated. 40 vibrational energy levels are observed in the ground state of Rn2 dimer. The last vibrational energy level is bound by only 0.0012 cm-1.

  15. Learning Approach on the Ground State Energy Calculation of Helium Atom

    SciTech Connect

    Shah, Syed Naseem Hussain

    2010-07-28

    This research investigated the role of learning approach on the ground state energy calculation of Helium atom in improving the concepts of science teachers at university level. As the exact solution of several particles is not possible here we used approximation methods. Using this method one can understand easily the calculation of ground state energy of any given function. Variation Method is one of the most useful approximation methods in estimating the energy eigen values of the ground state and the first few excited states of a system, which we only have a qualitative idea about the wave function.The objective of this approach is to introduce and involve university teacher in new research, to improve their class room practices and to enable teachers to foster critical thinking in students.

  16. On the Ground-State Energy and Local Pressure of an Inhomogeneous Bose Gas

    NASA Astrophysics Data System (ADS)

    Bobrov, V. B.; Trigger, S. A.

    2017-01-01

    The exact expression for the average kinetic energy of an inhomogeneous Bose gas in the ground state is obtained as a functional of the inhomogeneous density of the Bose-Einstein condensate. The result is based on existence of the off-diagonal long-range order in the single-particle density matrix for systems with a Bose-Einstein condensate. This makes it possible to avoid the use of anomalous averages. On this basis, the explicit expressions for the ground-state energy and the local pressure of an inhomogeneous Bose gas are derived within the self-consistent Hartree-Fock approximation.

  17. The role of correlation in the ground state energy of confined helium atom

    SciTech Connect

    Aquino, N.

    2014-01-14

    We analyze the ground state energy of helium atom confined by spherical impenetrable walls, and the role of the correlation energy in the total energy. The confinement of an atom in a cavity is one way in which we can model the effect of the external pressure on an atom. The calculations of energy of the system are carried out by the variational method. We find that the correlation energy remains almost constant for a range values of size of the boxes analyzed.

  18. Substrate ground state binding energy concentration is realized as transition state stabilization in physiological enzyme catalysis.

    PubMed

    Britt, Billy Mark

    2004-09-30

    Previously published kinetic data on the interactions of seventeen different enzymes with their physiological substrates are re-examined in order to understand the connection between ground state binding energy and transition state stabilization of the enzyme-catalyzed reactions. When the substrate ground state binding energies are normalized by the substrate molar volumes, binding of the substrate to the enzyme active site may be thought of as an energy concentration interaction; that is, binding of the substrate ground state brings in a certain concentration of energy. When kinetic data of the enzyme/substrate interactions are analyzed from this point of view, the following relationships are discovered: 1) smaller substrates possess more binding energy concentrations than do larger substrates with the effect dropping off exponentially, 2) larger enzymes (relative to substrate size) bind both the ground and transition states more tightly than smaller enzymes, and 3) high substrate ground state binding energy concentration is associated with greater reaction transition state stabilization. It is proposed that these observations are inconsistent with the conventional (Haldane) view of enzyme catalysis and are better reconciled with the shifting specificity model for enzyme catalysis.

  19. Optimal quasifree approximation: Reconstructing the spectrum from ground-state energies

    NASA Astrophysics Data System (ADS)

    Campos Venuti, Lorenzo

    2011-07-01

    The sequence of ground-state energy density at finite size, eL, provides much more information than usually believed. Having at our disposal eL for short lattice sizes, we show how to reconstruct an approximate quasiparticle dispersion for any interacting model. The accuracy of this method relies on the best possible quasifree approximation to the model, consistent with the observed values of the energy eL. We also provide a simple criterion to assess whether such a quasifree approximation is valid. As a side effect, our method is able to assess whether the nature of the quasiparticles is fermionic or bosonic together with the effective boundary conditions of the model. When applied to the spin-1/2 Heisenberg model, the method produces a band of Fermi quasiparticles very close to the exact one of des Cloizeaux and Pearson. The method is further tested on a spin-1/2 Heisenberg model with explicit dimerization and on a spin-1 chain with single-ion anisotropy. A connection with the Riemann hypothesis is also pointed out.

  20. On Asymptotic Stability in Energy Space of Ground States for Nonlinear Schrödinger Equations

    NASA Astrophysics Data System (ADS)

    Cuccagna, Scipio; Mizumachi, Tetsu

    2008-11-01

    We consider nonlinear Schrödinger equations iu_t +Δ u +β (|u|^2)u=0 , text{for} (t,x)in mathbb{R}× mathbb{R}^d, where d ≥ 3 and β is smooth. We prove that symmetric finite energy solutions close to orbitally stable ground states converge to a sum of a ground state and a dispersive wave as t → ∞ assuming the so called the Fermi Golden Rule (FGR) hypothesis. We improve the “sign condition” required in a recent paper by Gang Zhou and I.M.Sigal.

  1. On the ground state energy of the delta-function Fermi gas

    NASA Astrophysics Data System (ADS)

    Tracy, Craig A.; Widom, Harold

    2016-10-01

    The weak coupling asymptotics to order γ of the ground state energy of the delta-function Fermi gas, derived heuristically in the literature, is here made rigorous. Further asymptotics are in principle computable. The analysis applies to the Gaudin integral equation, a method previously used by one of the authors for the asymptotics of large Toeplitz matrices.

  2. Effect of temperature on the single-particle ground-state energy of a polar quantum dot with Gaussian confinement

    SciTech Connect

    Jahan, Luhluh K. Chatterjee, Ashok

    2016-05-23

    The temperature and size dependence of the ground-state energy of a polaron in a Gaussian quantum dot have been investigated by using a variational technique. It is found that the ground-state energy increases with increasing temperature and decreases with the size of the quantum dot. Also, it is found that the ground-state energy is larger for a three-dimensional quantum dot as compared to a two-dimensional dot.

  3. A new accurate ground-state potential energy surface of ethylene and predictions for rotational and vibrational energy levels

    SciTech Connect

    Delahaye, Thibault Rey, Michaël Tyuterev, Vladimir G.; Nikitin, Andrei; Szalay, Péter G.

    2014-09-14

    In this paper we report a new ground state potential energy surface for ethylene (ethene) C{sub 2}H{sub 4} obtained from extended ab initio calculations. The coupled-cluster approach with the perturbative inclusion of the connected triple excitations CCSD(T) and correlation consistent polarized valence basis set cc-pVQZ was employed for computations of electronic ground state energies. The fit of the surface included 82 542 nuclear configurations using sixth order expansion in curvilinear symmetry-adapted coordinates involving 2236 parameters. A good convergence for variationally computed vibrational levels of the C{sub 2}H{sub 4} molecule was obtained with a RMS(Obs.–Calc.) deviation of 2.7 cm{sup −1} for fundamental bands centers and 5.9 cm{sup −1} for vibrational bands up to 7800 cm{sup −1}. Large scale vibrational and rotational calculations for {sup 12}C{sub 2}H{sub 4}, {sup 13}C{sub 2}H{sub 4}, and {sup 12}C{sub 2}D{sub 4} isotopologues were performed using this new surface. Energy levels for J = 20 up to 6000 cm{sup −1} are in a good agreement with observations. This represents a considerable improvement with respect to available global predictions of vibrational levels of {sup 13}C{sub 2}H{sub 4} and {sup 12}C{sub 2}D{sub 4} and rovibrational levels of {sup 12}C{sub 2}H{sub 4}.

  4. Ground state energy of a non-integer number of particles with δ attractive interactions

    NASA Astrophysics Data System (ADS)

    Brunet, Éric; Derrida, Bernard

    2000-04-01

    We show how to define and calculate the ground state energy of a system of quantum particles with δ attractive interactions when the number of particles n is non-integer. The question is relevant to obtain the probability distribution of the free energy of a directed polymer in a random medium. When one expands the ground state energy in powers of the interaction, all the coefficients of the perturbation series are polynomials in n, allowing to define the perturbation theory for non-integer n. We develop a procedure to calculate all the cumulants of the free energy of the directed polymer and we give explicit, although complicated, expressions of the first three cumulants.

  5. Dynamics Near the Ground State for the Energy Critical Nonlinear Heat Equation in Large Dimensions

    NASA Astrophysics Data System (ADS)

    Collot, Charles; Merle, Frank; Raphaël, Pierre

    2017-05-01

    We consider the energy critical semilinear heat equation partial_tu = Δ u + |u|^{4/d-2}u, \\quad x \\in {R}^d and give a complete classification of the flow near the ground state solitary wave Q(x) = 1/(1+{|x|^2{d(d-2)})^{d-2/2}} in dimension {d ≥ 7}, in the energy critical topology and without radial symmetry assumption. Given an initial data {Q + ɛ_0} with {|\

  6. Ground state potential energy surfaces around selected atoms from resonant inelastic x-ray scattering.

    PubMed

    Schreck, Simon; Pietzsch, Annette; Kennedy, Brian; Såthe, Conny; Miedema, Piter S; Techert, Simone; Strocov, Vladimir N; Schmitt, Thorsten; Hennies, Franz; Rubensson, Jan-Erik; Föhlisch, Alexander

    2016-01-29

    Thermally driven chemistry as well as materials' functionality are determined by the potential energy surface of a systems electronic ground state. This makes the potential energy surface a central and powerful concept in physics, chemistry and materials science. However, direct experimental access to the potential energy surface locally around atomic centers and to its long-range structure are lacking. Here we demonstrate how sub-natural linewidth resonant inelastic soft x-ray scattering at vibrational resolution is utilized to determine ground state potential energy surfaces locally and detect long-range changes of the potentials that are driven by local modifications. We show how the general concept is applicable not only to small isolated molecules such as O2 but also to strongly interacting systems such as the hydrogen bond network in liquid water. The weak perturbation to the potential energy surface through hydrogen bonding is observed as a trend towards softening of the ground state potential around the coordinating atom. The instrumental developments in high resolution resonant inelastic soft x-ray scattering are currently accelerating and will enable broad application of the presented approach. With this multidimensional potential energy surfaces that characterize collective phenomena such as (bio)molecular function or high-temperature superconductivity will become accessible in near future.

  7. Ground state potential energy surfaces around selected atoms from resonant inelastic x-ray scattering

    NASA Astrophysics Data System (ADS)

    Schreck, Simon; Pietzsch, Annette; Kennedy, Brian; Såthe, Conny; Miedema, Piter S.; Techert, Simone; Strocov, Vladimir N.; Schmitt, Thorsten; Hennies, Franz; Rubensson, Jan-Erik; Föhlisch, Alexander

    2016-01-01

    Thermally driven chemistry as well as materials’ functionality are determined by the potential energy surface of a systems electronic ground state. This makes the potential energy surface a central and powerful concept in physics, chemistry and materials science. However, direct experimental access to the potential energy surface locally around atomic centers and to its long-range structure are lacking. Here we demonstrate how sub-natural linewidth resonant inelastic soft x-ray scattering at vibrational resolution is utilized to determine ground state potential energy surfaces locally and detect long-range changes of the potentials that are driven by local modifications. We show how the general concept is applicable not only to small isolated molecules such as O2 but also to strongly interacting systems such as the hydrogen bond network in liquid water. The weak perturbation to the potential energy surface through hydrogen bonding is observed as a trend towards softening of the ground state potential around the coordinating atom. The instrumental developments in high resolution resonant inelastic soft x-ray scattering are currently accelerating and will enable broad application of the presented approach. With this multidimensional potential energy surfaces that characterize collective phenomena such as (bio)molecular function or high-temperature superconductivity will become accessible in near future.

  8. Ground state potential energy surfaces around selected atoms from resonant inelastic x-ray scattering

    PubMed Central

    Schreck, Simon; Pietzsch, Annette; Kennedy, Brian; Såthe, Conny; Miedema, Piter S.; Techert, Simone; Strocov, Vladimir N.; Schmitt, Thorsten; Hennies, Franz; Rubensson, Jan-Erik; Föhlisch, Alexander

    2016-01-01

    Thermally driven chemistry as well as materials’ functionality are determined by the potential energy surface of a systems electronic ground state. This makes the potential energy surface a central and powerful concept in physics, chemistry and materials science. However, direct experimental access to the potential energy surface locally around atomic centers and to its long-range structure are lacking. Here we demonstrate how sub-natural linewidth resonant inelastic soft x-ray scattering at vibrational resolution is utilized to determine ground state potential energy surfaces locally and detect long-range changes of the potentials that are driven by local modifications. We show how the general concept is applicable not only to small isolated molecules such as O2 but also to strongly interacting systems such as the hydrogen bond network in liquid water. The weak perturbation to the potential energy surface through hydrogen bonding is observed as a trend towards softening of the ground state potential around the coordinating atom. The instrumental developments in high resolution resonant inelastic soft x-ray scattering are currently accelerating and will enable broad application of the presented approach. With this multidimensional potential energy surfaces that characterize collective phenomena such as (bio)molecular function or high-temperature superconductivity will become accessible in near future. PMID:26821751

  9. The Potential Energy Surface for the Electronic Ground State of H 2Se Derived from Experiment

    NASA Astrophysics Data System (ADS)

    Jensen, P.; Kozin, I. N.

    1993-07-01

    The present paper reports a determination of the potential energy surface for the electronic ground state of the hydrogen selenide molecule through a direct least-squares fitting to experimental data using the MORBID (Morse oscillator rigid bender internal dynamics) approach developed by P. Jensen [ J. Mol. Spectrosc.128, 478-501 (1988); J. Chem. Soc. Faraday Trans. 284, 1315-1340 (1988)]. We have fitted a selection of 303 rotation-vibration energy spacings of H 280Se, D 280Se, and HD 80Se involving J ≤ 5 with a root-mean-square deviation of 0.0975 cm -1 for the rotational energy spacings and 0.268 cm -1 for the vibrational spacings. In the fitting, 14 parameters were varied. On the basis of the fitted potential surface we have studied the cluster effect in the vibrational ground state of H 2Se, i.e., the formation of nearly degenerate, four-member groups of rotational energy levels [see I. N. Kozin, S. Klee, P. Jensen, O. L. Polyansky, and I. M. Pavlichenkov. J. Mol. Spectrosc., 158, 409-422 (1993), and references therein]. The cluster formation becomes more pronounced with increasing J. For example, four-fold clusters formed in the vibrational ground state of H 280Se at J = 40 are degenerate to within a few MHz. Our predictions of the D 280Se energy spectrum show that for this molecule, the cluster formation is displaced towards higher J values than arc found for H 280Se. In the vibrational ground state, the qualitative deviation from the usual rigid rotor picture starts at J = 12 for H 280Se and at J = 18 for D 280Se, in full agreement with predictions from semiclassical theory. An interpretation of the cluster eigenstates is discussed.

  10. Atoms and quantum dots with a large number of electrons: The ground-state energy

    SciTech Connect

    Kunz, Herve; Rueedi, Rico

    2010-03-15

    We compute the ground-state energy of atoms and quantum dots with a large number N of electrons. Both systems are described by a nonrelativistic Hamiltonian of electrons in a d-dimensional space. The electrons interact via the Coulomb potential. In the case of atoms (d=3), the electrons are attracted by the nucleus via the Coulomb potential. In the case of quantum dots (d=2), the electrons are confined by an external potential, whose shape can be varied. We show that the dominant terms of the ground-state energy are those given by a semiclassical Hartree-exchange energy, whose N{yields}{infinity} limit corresponds to Thomas-Fermi theory. This semiclassical Hartree-exchange theory creates oscillations in the ground-state energy as a function of N. These oscillations reflect the dynamics of a classical particle moving in the presence of the Thomas-Fermi potential. The dynamics is regular for atoms and some dots, but in general in the case of dots, the motion contains a chaotic component. We compute the correlation effects. They appear at the order NlnN for atoms, in agreement with available data. For dots, they appear at the order N.

  11. The benzene-argon ground-state intermolecular potential energy surface revisited.

    PubMed

    Capelo, Silvia Bouzón; Fernández, Berta; Koch, Henrik; Felker, Peter M

    2009-04-30

    The benzene-Ar ground-state S(0) intermolecular potential energy surface is evaluated using the coupled cluster singles and doubles model including connected triple corrections and the augmented correlation consistent polarized valence triple-zeta basis set extended with a set of 3s3p2d1f1g midbond functions. The surface is characterized by absolute minima of -390.1 cm(-1) where the argon atom is located on the benzene C(6) axis at distances of +/-3.536 A, and has a general shape close to the available ground-state S(0) and the first singlet S(1) and triplet T(1) excited-state surfaces. Using the potential, the intermolecular level structure of the complex is evaluated. The new intermolecular potential energy surface gives very accurate results and improves those previously available.

  12. Relativistic corrections to the ground-state energy of the positronium molecule

    SciTech Connect

    Bubin, Sergiy; Stanke, Monika; Kedziera, Dariusz; Adamowicz, Ludwik

    2007-06-15

    The leading-order relativistic corrections to the ground-state energy of the positronium molecule (Ps{sub 2}) have been computed within the framework of perturbation theory. As the zero-order wave function we used a highly accurate nonrelativistic variational expansion in terms of 6000 explicitly correlated Gaussians that yielded the lowest variational upper bound for this system to date. We also report some expectation values representing the properties of Ps{sub 2}.

  13. Ground-state energy of the electron liquid in ultrathin wires.

    PubMed

    Fogler, Michael M

    2005-02-11

    The ground-state energy and the density correlation function of the electron liquid in a thin one-dimensional wire are computed. The calculation is based on an approximate mapping of the problem with a realistic Coulomb interaction law onto exactly solvable models of mathematical physics. This approach becomes asymptotically exact in the limit of a small wire radius but remains numerically accurate even for modestly thin wires.

  14. Ground state spin and excitation energies in half-filled Lieb lattices

    NASA Astrophysics Data System (ADS)

    Ţolea, M.; Niţǎ, M.

    2016-10-01

    We present detailed spectral calculations for small Lieb lattices having up to N =4 number of cells, in the regime of half-filling, an instance of particular relevance for the nanomagnetism of discrete systems such as quantum dot arrays, due to the degenerate levels at midspectrum. While for the Hubbard interaction model—and even number of sites—the ground state spin is given by the Lieb theorem, the inclusion of long-range interaction—or odd number of sites—makes the spin state not known a priori, which justifies our approach. We calculate also the excitation energies, which are of experimental importance, and find significant variation induced by the interaction potential. One obtains insights on the mechanisms involved that impose as ground state the Lieb state with lower spin rather than the Hund one with maximum spin for the degenerate levels, showing this in the first and second orders of the interaction potential for the smaller lattices. The analytical results agree with the numerical ones, which are performed by exact diagonalization calculations or by a combined mean-field and configuration interaction method. While the Lieb state is always lower in energy than the Hund state, for strong long-range interaction, when possible, another minimal spin state is imposed as ground state.

  15. Calculated ground state potential surface and excitation energies for the copper trimer

    NASA Technical Reports Server (NTRS)

    Walch, S. P.; Laskowski, B. C.

    1986-01-01

    In the context of their relevance to catalysis and to materials science problems, transition metals and transition metal (TM) compounds are currently of considerable interest, and studies have been conducted of the copper trimer, Cu3. The present investigation is concerned with a study of the ground state surface and several groups of excited states in order to improve the understanding of the spectroscopy of Cu3. Differences of the current study from previous investigations are related to an employment of larger basis sets and a more extensive electron correlation. This was done with the objective to obtain a more accurate definition of the ground state surface. Features of the bonding in the copper dimer are considered to obtain a basis for an understanding of the copper trimer. Attention is given to calculational details, the ground state surface, and calculated vertical excitation energies. The results of SCF/SDCI calculations are reported for portions of the ground surface, for two groups of excited states, and for the ionization potential of Cu3.

  16. Dissociation energy of the ground state of the CuH molecule

    NASA Astrophysics Data System (ADS)

    Rao, V. M.; Rao, M. L. P.; Rao, P. T.

    1981-06-01

    The dissociation energy of the ground state of the CuH molecule, which is observed in sun spots and in 19 Piscium, is evaluated by fitting the Hulburt-Hirschfelder function to the RKRV curve. The Hulburt-Hirschfelder potential is shown to reproduce the true curve more accurately than does the Lippincott function. The value obtained for the dissociation energy is 2.84 eV, while the values reported by Herzberg (1950) and Beckel et al. (1971) are less than 2.89 eV and 2.80 + or - 0.12 eV, respectively.

  17. Ground-state energy of the interacting Bose gas in two dimensions: An explicit construction

    SciTech Connect

    Beane, Silas R.

    2010-12-15

    The isotropic scattering phase shift is calculated for nonrelativistic bosons interacting at low energies via an arbitrary finite-range potential in d space-time dimensions. Scattering on a (d-1)-dimensional torus is then considered, and the eigenvalue equation relating the energy levels on the torus to the scattering phase shift is derived. With this technology in hand, and focusing on the case of two spatial dimensions, a perturbative expansion is developed for the ground-state energy of N identical bosons which interact via an arbitrary finite-range potential in a finite area. The leading nonuniversal effects due to range corrections and three-body forces are included. It is then shown that the thermodynamic limit of the ground-state energy in a finite area can be taken in closed form to obtain the energy per particle in the low-density expansion by explicitly summing the parts of the finite-area energy that diverge with powers of N. The leading and subleading finite-size corrections to the thermodynamic limit equation of state are also computed. Closed-form results--some well known, others perhaps not--for two-dimensional lattice sums are included in an Appendix.

  18. Kinetic energy partition method applied to ground state helium-like atoms

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Hsin; Chao, Sheng D.

    2017-03-01

    We have used the recently developed kinetic energy partition (KEP) method to solve the quantum eigenvalue problems for helium-like atoms and obtain precise ground state energies and wave-functions. The key to treating properly the electron-electron (repulsive) Coulomb potential energies for the KEP method to be applied is to introduce a "negative mass" term into the partitioned kinetic energy. A Hartree-like product wave-function from the subsystem wave-functions is used to form the initial trial function, and the variational search for the optimized adiabatic parameters leads to a precise ground state energy. This new approach sheds new light on the all-important problem of solving many-electron Schrödinger equations and hopefully opens a new way to predictive quantum chemistry. The results presented here give very promising evidence that an effective one-electron model can be used to represent a many-electron system, in the spirit of density functional theory.

  19. Dynamic Electron Correlation Effects on the Ground State Potential Energy Surface of a Retinal Chromophore Model.

    PubMed

    Gozem, Samer; Huntress, Mark; Schapiro, Igor; Lindh, Roland; Granovsky, Alexander A; Angeli, Celestino; Olivucci, Massimo

    2012-11-13

    The ground state potential energy surface of the retinal chromophore of visual pigments (e.g., bovine rhodopsin) features a low-lying conical intersection surrounded by regions with variable charge-transfer and diradical electronic structures. This implies that dynamic electron correlation may have a large effect on the shape of the force fields driving its reactivity. To investigate this effect, we focus on mapping the potential energy for three paths located along the ground state CASSCF potential energy surface of the penta-2,4-dieniminium cation taken as a minimal model of the retinal chromophore. The first path spans the bond length alternation coordinate and intercepts a conical intersection point. The other two are minimum energy paths along two distinct but kinetically competitive thermal isomerization coordinates. We show that the effect of introducing the missing dynamic electron correlation variationally (with MRCISD) and perturbatively (with the CASPT2, NEVPT2, and XMCQDPT2 methods) leads, invariably, to a stabilization of the regions with charge transfer character and to a significant reshaping of the reference CASSCF potential energy surface and suggesting a change in the dominating isomerization mechanism. The possible impact of such a correction on the photoisomerization of the retinal chromophore is discussed.

  20. Kinetic energy partition method applied to ground state helium-like atoms.

    PubMed

    Chen, Yu-Hsin; Chao, Sheng D

    2017-03-28

    We have used the recently developed kinetic energy partition (KEP) method to solve the quantum eigenvalue problems for helium-like atoms and obtain precise ground state energies and wave-functions. The key to treating properly the electron-electron (repulsive) Coulomb potential energies for the KEP method to be applied is to introduce a "negative mass" term into the partitioned kinetic energy. A Hartree-like product wave-function from the subsystem wave-functions is used to form the initial trial function, and the variational search for the optimized adiabatic parameters leads to a precise ground state energy. This new approach sheds new light on the all-important problem of solving many-electron Schrödinger equations and hopefully opens a new way to predictive quantum chemistry. The results presented here give very promising evidence that an effective one-electron model can be used to represent a many-electron system, in the spirit of density functional theory.

  1. Parisi Formula, Disorder Chaos and Fluctuation for the Ground State Energy in the Spherical Mixed p-Spin Models

    NASA Astrophysics Data System (ADS)

    Chen, Wei-Kuo; Sen, Arnab

    2016-12-01

    We show that the limiting ground state energy of the spherical mixed p-spin model can be identified as the infimum of certain variational problem. This complements the well-known Parisi formula for the limiting free energy in the spherical model. As an application, we obtain explicit formulas for the limiting ground state energy in the replica symmetry, one level of replica symmetry breaking and full replica symmetry breaking phases at zero temperature. In addition, our approach leads to new results on disorder chaos in spherical mixed even p-spin models. In particular, we prove that when there is no external field, the location of the ground state energy is chaotic under small perturbations of the disorder. We also establish that in the spherical mixed even p-spin model, the ground state energy superconcentrates in the absence of external field, while it obeys a central limit theorem if the external field is present.

  2. Two-loop self-energy for the ground state of medium-Z hydrogenlike ions

    SciTech Connect

    Yerokhin, V. A.

    2009-10-15

    The two-loop self-energy correction to the ground-state Lamb shift is calculated for hydrogenlike ions with the nuclear charge Z=10-30 without any expansion in the binding field of the nucleus. A calculational technique is reported for treatment of Feynman diagrams in the mixed coordinate-momentum representation, which yields significant improvement in numerical accuracy as compared to previous results. An extrapolation of the all-order numerical data yields a result for the higher-order remainder function for hydrogen. The previously reported disagreement between the all-order and the perturbative approaches is reduced to the marginal agreement.

  3. Effects of a scattering center on the ground-state energy of quantum-dot lithium

    NASA Astrophysics Data System (ADS)

    Vatansever, Z. D.; Sakiroglu, S.; Sokmen, I.

    2017-03-01

    In this paper, the effects of a repulsive scattering center on the ground-state energy and spin properties of a three-electron parabolic quantum dot are investigated theoretically by means of configuration interaction method. Phase transition from a weakly correlated regime to a strongly correlated regime is examined from several strengths and positions of Gaussian impurity. Numerical results reveal that the transition from spin-1/2 to spin-3/2 state depends strongly on the location of the impurity which accordingly states the controllability of the spin polarization. Moreover, broken circular symmetry results in more pronounced electronic charge localization.

  4. The ground-state energy of the ± J sping glass. A comparison of various biologically motivated algorithms

    NASA Astrophysics Data System (ADS)

    Gropengiesser, Uwe

    1995-06-01

    We compare various evlutionary strategies to determine the ground-state energy of the ± J spin glass. We show that the choice of different evolution laws is less important than a suitable treatment of the "free spins" of the system At least one combination of these strategies does not give the correct results, but the ground states of the other different strategies coincide. Therefore we are able to extrapolate the infinit-size ground-state energy for the square lattice to -1.401±0.0015 and for the simple cubic lattice to -1.786±0.004.

  5. Spectroscopic determination of the ground-state dissociation energy and isotopic shift of NaD

    NASA Astrophysics Data System (ADS)

    Chu, Chia-Ching; He, Wei-Fung; Lin, Rong-Sin; Li, Yin-Ji; Whang, Thou-Jen; Tsai, Chin-Chun

    2017-07-01

    Stimulated emission pumping with fluorescence depletion spectroscopy is used to determine the NaD X 1Σ+ ground-state dissociation energy and its isotopic shift. A total of 230 rovibrational levels in the range 9 ≤ v″ ≤ 29 and 1 ≤ J″ ≤ 11 are observed, where v″ = 29 is about 50 cm-1 below the dissociation limit. Analysis of the highest five vibrational levels yields the dissociation energy De = 15 822 ± 5 cm-1 with a vibrational quantum number at dissociation vD = 31.2 ± 0.1. The energy difference in the well depth of this isotopologue with respect to that of NaH is δDe = De(NaH) - De(NaD) = -7 cm-1. A new set of Dunham coefficients is derived to fit all the observed energy levels to within the experimental uncertainty.

  6. An upper limit to ground state energy fluctuations in nuclear masses

    SciTech Connect

    Hirsch, Jorge G.; Frank, Alejandro; Barea, Jose; Velazquez, Victor; Isacker, Piet van; Zuker, Andres P.

    2007-02-12

    Shell model calculations are employed to estimate un upper limit of statistical fluctuations in the nuclear ground state energies. In order to mimic the presence of quantum chaos associated with neutron resonances at energies between 6 to 10 MeV, calculations include random interactions in the upper shells. The upper bound for the energy fluctuations at mid-shell is shown to have the form {sigma}(A) {approx_equal} 20A-1.34 MeV. This estimate is consistent with the mass errors found in large shell model calculations along the N=126 line, and with local mass error estimated using the Garvey-Kelson relations, all being smaller than 100 keV.

  7. A ground-state-directed optimization scheme for the Kohn-Sham energy.

    PubMed

    Høst, Stinne; Jansík, Branislav; Olsen, Jeppe; Jørgensen, Poul; Reine, Simen; Helgaker, Trygve

    2008-09-21

    Kohn-Sham density-functional calculations are used in many branches of science to obtain information about the electronic structure of molecular systems and materials. Unfortunately, the traditional method for optimizing the Kohn-Sham energy suffers from fundamental problems that may lead to divergence or, even worse, convergence to an energy saddle point rather than to the ground-state minimum--in particular, for the larger and more complicated electronic systems that are often studied by Kohn-Sham theory nowadays. We here present a novel method for Kohn-Sham energy minimization that does not suffer from the flaws of the conventional approach, combining reliability and efficiency with linear complexity. In particular, the proposed method converges by design to a minimum, avoiding the sometimes spurious solutions of the traditional method and bypassing the need to examine the structure of the provided solution.

  8. An upper limit of ground-state energy fluctuations in nuclear masses

    NASA Astrophysics Data System (ADS)

    Hirsch, Jorge G.; Velázquez, Víctor; Frank, Alejandro; Barea, José; Van Isacker, Piet; Zuker, Andrés P.

    2006-07-01

    Shell model calculations are employed to estimate an upper limit of statistical fluctuations in the nuclear ground-state energies. In order to mimic the presence of quantum chaos associated with neutron resonances at energies between 6 and 10 MeV, calculations include random interactions in the upper shells. The upper bound for the energy fluctuations at mid-shell is shown to have the form σ(A)ap20 A-1.34 MeV. This estimate is consistent with the mass errors found in large-shell model calculations along the N=126 line, and with local mass error estimated using the Garvey-Kelson relations, all being smaller than 100 keV. It agrees in both size and functional form with the fluctuations deduced independently from second-order perturbation theory.

  9. An upper limit to ground state energy fluctuations in nuclear masses

    NASA Astrophysics Data System (ADS)

    Hirsch, Jorge G.; Velázquez, Víctor; Frank, Alejandro; Barea, José; Van Isacker, Piet; Zuker, Andrés P.

    2007-02-01

    Shell model calculations are employed to estimate un upper limit of statistical fluctuations in the nuclear ground state energies. In order to mimic the presence of quantum chaos associated with neutron resonances at energies between 6 to 10 MeV, calculations include random interactions in the upper shells. The upper bound for the energy fluctuations at mid-shell is shown to have the form σ(A) ≈ 20A-1.34 MeV. This estimate is consistent with the mass errors found in large shell model calculations along the N=126 line, and with local mass error estimated using the Garvey-Kelson relations, all being smaller than 100 keV.

  10. Triaxiality of the ground states in the 174W

    NASA Astrophysics Data System (ADS)

    Ya, Tu; Chen, Y. S.; Liu, L.; Gao, Z. C.

    2016-05-01

    We have performed calculations for the ground states in 174W by using the projected total energy surface (PTES) calculations. Both the ground state (g.s.) band and its γ band reproduce the experimental data. Further discussion about the triaxiality in 174W has been made by transition quardrupole moment (Qt) and comparing between the PTES and TRS methods.

  11. Full-dimensional analytical ab initio potential energy surface of the ground state of HOI.

    PubMed

    de Oliveira-Filho, Antonio G S; Aoto, Yuri A; Ornellas, Fernando R

    2011-07-28

    Extensive ab initio calculations using a complete active space second-order perturbation theory wavefunction, including scalar and spin-orbit relativistic effects with a quadruple-zeta quality basis set were used to construct an analytical potential energy surface (PES) of the ground state of the [H, O, I] system. A total of 5344 points were fit to a three-dimensional function of the internuclear distances, with a global root-mean-square error of 1.26 kcal mol(-1). The resulting PES describes accurately the main features of this system: the HOI and HIO isomers, the transition state between them, and all dissociation asymptotes. After a small adjustment, using a scaling factor on the internal coordinates of HOI, the frequencies calculated in this work agree with the experimental data available within 10 cm(-1).

  12. Full-dimensional analytical ab initio potential energy surface of the ground state of HOI

    NASA Astrophysics Data System (ADS)

    de Oliveira-Filho, Antonio G. S.; Aoto, Yuri A.; Ornellas, Fernando R.

    2011-07-01

    Extensive ab initio calculations using a complete active space second-order perturbation theory wavefunction, including scalar and spin-orbit relativistic effects with a quadruple-zeta quality basis set were used to construct an analytical potential energy surface (PES) of the ground state of the [H, O, I] system. A total of 5344 points were fit to a three-dimensional function of the internuclear distances, with a global root-mean-square error of 1.26 kcal mol-1. The resulting PES describes accurately the main features of this system: the HOI and HIO isomers, the transition state between them, and all dissociation asymptotes. After a small adjustment, using a scaling factor on the internal coordinates of HOI, the frequencies calculated in this work agree with the experimental data available within 10 cm-1.

  13. Analytic variational calculation of the ground-state binding energy of hydrogen in intermediate and intense magnetic fields

    NASA Technical Reports Server (NTRS)

    Wilson, L. W.

    1974-01-01

    The present work investigates analytically the effect of an intermediate or intense magnetic field, such as probably exist in white dwarfs and near pulsars, on the binding energy of the hydrogen ground state. A wave-function 'prescription' is given for an analytic variational calculation of the binding energy. The calculation still gives a smooth transition between intermediate and intense fields. An explicit calculation of the ground-state binding energy as B goes to infinity is provided for the Yafet et al. (1956) trial function.

  14. Analytic variational calculation of the ground-state binding energy of hydrogen in intermediate and intense magnetic fields

    NASA Technical Reports Server (NTRS)

    Wilson, L. W.

    1974-01-01

    The present work investigates analytically the effect of an intermediate or intense magnetic field, such as probably exist in white dwarfs and near pulsars, on the binding energy of the hydrogen ground state. A wave-function 'prescription' is given for an analytic variational calculation of the binding energy. The calculation still gives a smooth transition between intermediate and intense fields. An explicit calculation of the ground-state binding energy as B goes to infinity is provided for the Yafet et al. (1956) trial function.

  15. Decomposition of Pyruvic Acid on the Ground-State Potential Energy Surface.

    PubMed

    da Silva, Gabriel

    2016-01-21

    A potential energy surface is reported for isomerization and decomposition of gas-phase pyruvic acid (CH3C(O)C(O)OH) in its ground electronic state. Consistent with previous works, the lowest energy pathway for pyruvic acid decomposition is identified as decarboxylation to produce hydroxymethylcarbene (CH3COH), with overall barrier of 43 kcal mol(-1). This study discovers that pyruvic acid can also isomerize to the α-lactone form with a barrier of only 36 kcal mol(-1), from which CO elimination can occur at 49 kcal mol(-1) above pyruvic acid. An additional novel channel is identified for the tautomerisation of pyruvic acid to the enol form, via a double H-shift mechanism. The barrier for this process is 51 kcal mol(-1), which is around 20 kcal mol(-1) lower than the barrier for conventional keto-enol tautomerization via a 1,3-H shift transition state. Rate coefficients are calculated for pyruvic acid decomposition through RRKM theory/master equation simulations at 800-2000 K and 1 atm, showing good agreement with the available experimental data. The dissociation of vibrationally excited pyruvic acid produced through photoexcitation and subsequent internal conversion to the ground state is also modeled under tropospheric conditions and is seen to produce appreciable quantities of CO (∼1-4%) in addition to CH3COH via the dominant CO2 loss channel.

  16. Ab initio ground-state potential energy function and vibration-rotation energy levels of imidogen, NH.

    PubMed

    Koput, Jacek

    2015-06-30

    The accurate ground-state potential energy function of imidogen, NH, has been determined from ab initio calculations using the multireference averaged coupled-pair functional (MR-ACPF) method in conjunction with the correlation-consistent core-valence basis sets up to octuple-zeta quality. The importance of several effects, including electron correlation beyond the MR-ACPF level of approximation, the scalar relativistic, adiabatic, and nonadiabatic corrections were discussed. Along with the large one-particle basis set, all of these effects were found to be crucial to attain "spectroscopic" accuracy of the theoretical predictions of vibration-rotation energy levels of NH.

  17. Expansion of the energy of the ground state of the Gross-Pitaevskii equation in the Thomas-Fermi limit

    NASA Astrophysics Data System (ADS)

    Gallo, Clément

    2013-03-01

    From the asymptotic expansion of the ground state of the Gross-Pitaevskii equation in the Thomas-Fermi limit given by Gallo and Pelinovsky ["On the Thomas-Fermi ground state in a harmonic potential," Asymptot. Anal. 73(1-2), 53-96 (2011)], 10.3233/ASY-2011-1034, we infer an asymptotic expansion of the kinetic, potential, and total energy of the ground state. In particular, we give a rigorous proof of the expansion of the kinetic energy calculated by Dalfovo, Pitaevskii, and Stringari ["Order parameter at the boundary of a trapped Bose gas," Phys. Rev. A 54, 4213-4217 (1996)], 10.1103/PhysRevA.54.4213 in the case where the space dimension is 3. Moreover, we calculate one more term in this expansion, and we generalize the result to space dimensions 1 and 2.

  18. Determination of the Effective Ground State Potential Energy Function of Ozone from High-Resolution Infrared Spectra.

    PubMed

    Tyuterev; Tashkun; Jensen; Barbe; Cours

    1999-11-01

    The effective ground state potential energy function of the ozone molecule near the C(2v) equilibrium configuration was obtained in a least-squares fit to the largest sample of experimental, high-resolution vibration-rotation data used for this purpose so far. The fitting is based on variational calculations carried out with the extended Morse Oscillator Rigid Bender Internal Dynamics model. The potential function is expanded in Morse-type functions of the stretching variables and in cosine of the bending angle. The present calculation produces results in significantly better agreement with experiment than previous determinations of the potential energy surface, and the energies predicted with the new surface are sufficiently accurate to be useful for the assignment of new high-resolution spectra. The rms (root-mean-square) deviation of the fit of rovibrational data up to J = 5 is 0.02 cm(-1). For the set of all 60 band centers of the (16)O(3) molecule included in the Atlas of Ozone Line Parameters, the rms deviation is 0.025 cm(-1), and for all band centers determined so far from high-resolution spectra, including those recently observed and assigned in Reims corresponding to highly excited stretching and bending vibrations (v(1) + v(2) + v(3) = 6), the rms deviation is 0.1 cm(-1). The "dark states" that produce resonance perturbations in the observed bands are described with experimental accuracy up to the (v(1)v(2)v(3)) = (080) state. Extrapolation tests demonstrate the predictive power of the potential function obtained: rotational extrapolation up to J = 10 for the 11 lowest vibrational states results in an rms deviation of 0.06cm(-1). Also, vibrational energies measured by low-resolution Raman spectroscopy (which were not included in the input data for the fit) are calculated within the experimental accuracy (rms = 1.6 cm(-1)) of the experimental values up to the dissociation limit. The statistical analysis suggests that the accuracy of the equilibrium

  19. Theoretical Electric Dipole Moments and Dissociation Energies for the Ground States of GaH-BrH

    NASA Technical Reports Server (NTRS)

    Pettersson, Lars G. M.; Langhoff, Stephen R.

    1986-01-01

    Reliable experimental diople moments are available for the ground states of SeH and BrH whereas no values have been reported for GaH and AsH a recently reported experimental dipole moment for GeH of 1.24 + or -0.01 D has been seriously questioned, and a much lower value of, 0.1 + or - 0.05 D, suggested. In this work, we report accurate theoretical dipole moments, dipole derivatives, dissociation energies, and spectroscopic constants (tau(sub e), omega(sub e)) for the ground states of GaH through BrH.

  20. Theoretical Electric Dipole Moments and Dissociation Energies for the Ground States of GaH-BrH

    NASA Technical Reports Server (NTRS)

    Pettersson, Lars G. M.; Langhoff, Stephen R.

    1986-01-01

    Reliable experimental diople moments are available for the ground states of SeH and BrH whereas no values have been reported for GaH and AsH a recently reported experimental dipole moment for GeH of 1.24 + or -0.01 D has been seriously questioned, and a much lower value of, 0.1 + or - 0.05 D, suggested. In this work, we report accurate theoretical dipole moments, dipole derivatives, dissociation energies, and spectroscopic constants (tau(sub e), omega(sub e)) for the ground states of GaH through BrH.

  1. Using Uncertainty Principle to Find the Ground-State Energy of the Helium and a Helium-like Hookean Atom

    ERIC Educational Resources Information Center

    Harbola, Varun

    2011-01-01

    In this paper, we accurately estimate the ground-state energy and the atomic radius of the helium atom and a helium-like Hookean atom by employing the uncertainty principle in conjunction with the variational approach. We show that with the use of the uncertainty principle, electrons are found to be spread over a radial region, giving an electron…

  2. Using Uncertainty Principle to Find the Ground-State Energy of the Helium and a Helium-like Hookean Atom

    ERIC Educational Resources Information Center

    Harbola, Varun

    2011-01-01

    In this paper, we accurately estimate the ground-state energy and the atomic radius of the helium atom and a helium-like Hookean atom by employing the uncertainty principle in conjunction with the variational approach. We show that with the use of the uncertainty principle, electrons are found to be spread over a radial region, giving an electron…

  3. Ground-state energy of the q-state Potts model: The minimum modularity.

    PubMed

    Lee, J S; Hwang, S; Yeo, J; Kim, D; Kahng, B

    2014-11-01

    A wide range of interacting systems can be described by complex networks. A common feature of such networks is that they consist of several communities or modules, the degree of which may quantified as the modularity. However, even a random uncorrelated network, which has no obvious modular structure, has a finite modularity due to the quenched disorder. For this reason, the modularity of a given network is meaningful only when it is compared with that of a randomized network with the same degree distribution. In this context, it is important to calculate the modularity of a random uncorrelated network with an arbitrary degree distribution. The modularity of a random network has been calculated [Reichardt and Bornholdt, Phys. Rev. E 76, 015102 (2007)PLEEE81539-375510.1103/PhysRevE.76.015102]; however, this was limited to the case whereby the network was assumed to have only two communities, and it is evident that the modularity should be calculated in general with q(≥2) communities. Here we calculate the modularity for q communities by evaluating the ground-state energy of the q-state Potts Hamiltonian, based on replica symmetric solutions assuming that the mean degree is large. We found that the modularity is proportional to 〈sqrt[k]〉/〈k〉 regardless of q and that only the coefficient depends on q. In particular, when the degree distribution follows a power law, the modularity is proportional to 〈k〉^{-1/2}. Our analytical results are confirmed by comparison with numerical simulations. Therefore, our results can be used as reference values for real-world networks.

  4. Ionization energies and term energies of the ground states 1s22s of lithium-like systems

    NASA Astrophysics Data System (ADS)

    Li, Jin-Ying; Wang, Zhi-Wen

    2014-01-01

    We extend the Hamiltonian method of the full-core plus correlation (FCPC) by minimizing the expectation value to calculate the non-relativistic energies and the wave functions of 1s22s states for the lithium-like systems from Z = 41 to 50. The mass-polarization and the relativistic corrections including the kinetic-energy correction, the Darwin term, the electron—electron contact term, and the orbit—orbit interaction are calculated perturbatively as first-order correction. The contribution from quantum electrodynamic (QED) is also explored by using the effective nuclear charge formula. The ionization potential and term energies of the ground states 1s22s are derived and compared with other theoretical calculation results. It is shown that the FCPC methods are also effective for theoretical calculation of the ionic structure for high nuclear ion of lithium-like systems.

  5. Face-dependent Auger neutralization and ground-state energy shift for He in front of Al surfaces

    SciTech Connect

    Wethekam, S.; Winter, H.; Valdes, Diego; Monreal, R. C.

    2008-08-15

    He atoms and ions with keV energies are scattered under grazing angles of incidence from Al(111), Al(100), and Al(110) surfaces. Fractions of surviving ions and normal energy gains of He{sup +} ions prior to neutralization, derived from shifts of angular distributions for incident atoms and ions, are compared to results from three-dimensional Monte Carlo simulations based on theoretically calculated Auger neutralization rates and He ground-state energy shifts. From the good agreement of experimental data with simulations, we conclude a detailed microscopic understanding for a model system of ion-surface interactions. Our work provides further evidence for the recently reported surface Miller index dependence for the neutralization of He{sup +} ions at metal surfaces. The study is extended to the face dependence of the He ground-state energy shift.

  6. The ground state tunneling splitting and the zero point energy of malonaldehyde: a quantum Monte Carlo determination.

    PubMed

    Viel, Alexandra; Coutinho-Neto, Maurício D; Manthe, Uwe

    2007-01-14

    Quantum dynamics calculations of the ground state tunneling splitting and of the zero point energy of malonaldehyde on the full dimensional potential energy surface proposed by Yagi et al. [J. Chem. Phys. 1154, 10647 (2001)] are reported. The exact diffusion Monte Carlo and the projection operator imaginary time spectral evolution methods are used to compute accurate benchmark results for this 21-dimensional ab initio potential energy surface. A tunneling splitting of 25.7+/-0.3 cm-1 is obtained, and the vibrational ground state energy is found to be 15 122+/-4 cm-1. Isotopic substitution of the tunneling hydrogen modifies the tunneling splitting down to 3.21+/-0.09 cm-1 and the vibrational ground state energy to 14 385+/-2 cm-1. The computed tunneling splittings are slightly higher than the experimental values as expected from the potential energy surface which slightly underestimates the barrier height, and they are slightly lower than the results from the instanton theory obtained using the same potential energy surface.

  7. Rabi-coupled two-component Bose-Einstein condensates: Classification of the ground states, defects, and energy estimates

    NASA Astrophysics Data System (ADS)

    Aftalion, Amandine; Mason, Peter

    2016-08-01

    We classify the ground states and topological defects of two-component Bose-Einstein condensates under the effect of internal coherent Rabi coupling. We present numerical phase diagrams which show the boundaries between symmetry-breaking components and various vortex patterns (triangular, square, bound state between vortices). We estimate the Rabi energy in the Thomas-Fermi limit which allows us to have an analytical description of the point energy leading to the formation of the various vortex patterns.

  8. Hylleraas-configuration-interaction nonrelativistic energies for the {sup 1}S ground states of the beryllium isoelectronic sequence

    SciTech Connect

    Sims, James S.; Hagstrom, Stanley A.

    2014-06-14

    In a previous work, Sims and Hagstrom [“Hylleraas-configuration-interaction study of the 1 {sup 1}S ground state of neutral beryllium,” Phys. Rev. A 83, 032518 (2011)] reported Hylleraas-configuration-interaction (Hy-CI) method variational calculations for the {sup 1}S ground state of neutral beryllium with an estimated accuracy of a tenth of a microhartree. In this work, the calculations have been extended to higher accuracy and, by simple scaling of the orbital exponents, to the entire Be 2 {sup 1}S isoelectronic sequence. The best nonrelativistic energies for Be, B{sup +}, and C{sup ++} obtained are −14.6673 5649 269, −24.3488 8446 36, and −36.5348 5236 25 hartree, respectively. Except for Be, all computed nonrelativistic energies are superior to the known reference energies for these states.

  9. Hylleraas-configuration-interaction nonrelativistic energies for the ¹S ground states of the beryllium isoelectronic sequence.

    PubMed

    Sims, James S; Hagstrom, Stanley A

    2014-06-14

    In a previous work, Sims and Hagstrom ["Hylleraas-configuration-interaction study of the 1 (1)S ground state of neutral beryllium," Phys. Rev. A 83, 032518 (2011)] reported Hylleraas-configuration-interaction (Hy-CI) method variational calculations for the (1)S ground state of neutral beryllium with an estimated accuracy of a tenth of a microhartree. In this work, the calculations have been extended to higher accuracy and, by simple scaling of the orbital exponents, to the entire Be 2 (1)S isoelectronic sequence. The best nonrelativistic energies for Be, B(+), and C(++) obtained are -14.6673 5649 269, -24.3488 8446 36, and -36.5348 5236 25 hartree, respectively. Except for Be, all computed nonrelativistic energies are superior to the known reference energies for these states.

  10. Ground state energy of an exciton in a spherical quantum dot in the presence of an external magnetic field

    SciTech Connect

    Jahan K, Luhluh Boda, Aalu; Chatterjee, Ashok

    2015-05-15

    The problem of an exciton trapped in a three dimensional Gaussian quantum dot is studied in the presence of an external magnetic field. A variational method is employed to obtain the ground state energy of the exciton as a function of the quantum dot size, the confinement strength and the magnetic field. It is also shown that the variation of the size of the exciton with the radius of the quantum dot.

  11. A QM/MM Approach Using the AMOEBA Polarizable Embedding: From Ground State Energies to Electronic Excitations.

    PubMed

    Loco, Daniele; Polack, Étienne; Caprasecca, Stefano; Lagardère, Louis; Lipparini, Filippo; Piquemal, Jean-Philip; Mennucci, Benedetta

    2016-08-09

    A fully polarizable implementation of the hybrid quantum mechanics/molecular mechanics approach is presented, where the classical environment is described through the AMOEBA polarizable force field. A variational formalism, offering a self-consistent relaxation of both the MM induced dipoles and the QM electronic density, is used for ground state energies and extended to electronic excitations in the framework of time-dependent density functional theory combined with a state specific response of the classical part. An application to the calculation of the solvatochromism of the pyridinium N-phenolate betaine dye used to define the solvent ET(30) scale is presented. The results show that the QM/AMOEBA model not only properly describes specific and bulk effects in the ground state but it also correctly responds to the large change in the solute electronic charge distribution upon excitation.

  12. Exponential vanishing of the ground-state gap of the quantum random energy model via adiabatic quantum computing

    SciTech Connect

    Adame, J.; Warzel, S.

    2015-11-15

    In this note, we use ideas of Farhi et al. [Int. J. Quantum. Inf. 6, 503 (2008) and Quantum Inf. Comput. 11, 840 (2011)] who link a lower bound on the run time of their quantum adiabatic search algorithm to an upper bound on the energy gap above the ground-state of the generators of this algorithm. We apply these ideas to the quantum random energy model (QREM). Our main result is a simple proof of the conjectured exponential vanishing of the energy gap of the QREM.

  13. Separability of spin-orbit and correlation energies for the sixth-row main group hydride ground states

    NASA Astrophysics Data System (ADS)

    DiLabio, Gino A.; Christiansen, Phillip A.

    1998-05-01

    The spin-orbit energy contributions to the ground state potential energy curves for the main group hydrides, TIH through AtH are estimated by differencing multireference, single promotion, configuration interaction (MRS-CI) energies with and without the spin-orbit operator. The spin-orbit contributions are then summed into the energies determined at the λ-s MRSD-CI level (both single and double promotions). The agreement between the resultant curves and those obtained using intermediate coupling MRSD-CI is within 1.2 kcal/mol over a range of internuclear separations. This suggests that, contrary to previous arguments, spin-orbit coupling and correlation energies are very nearly separable for the main group hydride ground states. Furthermore, the computational effort expended by this separate evaluation is up to 12 times less than that for a comparable intermediate coupling CI. The analysis of some properties of these hydrides indicates that bond length shifts due to spin-orbit coupling are small (0.03 Å) while harmonic vibrational frequencies decrease by up to 9%. Dissociation energies are predicted to change considerably in the presence of the operator in agreement with previous findings.

  14. The Ground State of a Gross-Pitaevskii Energy with General Potential in the Thomas-Fermi Limit

    NASA Astrophysics Data System (ADS)

    Karali, Georgia; Sourdis, Christos

    2015-08-01

    We study the ground state which minimizes a Gross-Pitaevskii energy with general non-radial trapping potential, under the unit mass constraint, in the Thomas-Fermi limit where a small parameter tends to 0. This ground state plays an important role in the mathematical treatment of recent experiments on the phenomenon of Bose-Einstein condensation, and in the study of various types of solutions of nonhomogeneous defocusing nonlinear Schrödinger equations. Many of these applications require delicate estimates for the behavior of the ground state near the boundary of the condensate, as , in the vicinity of which the ground state has irregular behavior in the form of a steep corner layer. In particular, the role of this layer is important in order to detect the presence of vortices in the small density region of the condensate, to understand the superfluid flow around an obstacle, and it also has a leading order contribution in the energy. In contrast to previous approaches, we utilize a perturbation argument to go beyond the classical Thomas-Fermi approximation and accurately approximate the layer by the Hastings-McLeod solution of the Painlevé-II equation. This settles an open problem (cf. Aftalion in Vortices in Bose Einstein Condensates. Birkhäuser Boston, Boston, 2006, pg. 13 or Open Problem 8.1), answered very recently only for the special case of the model harmonic potential (Gallo and Pelinovsky in Asymptot Anal 73:53-96, 2011). In fact, we even improve upon previous results that relied heavily on the radial symmetry of the potential trap. Moreover, we show that the ground state has the maximal regularity available, namely it remains uniformly bounded in the -Hölder norm, which is the exact Hölder regularity of the singular limit profile, as . Our study is highly motivated by an interesting open problem posed recently by A ftalion, Jerrard, and R oyo-L etelier (J Funct Anal 260:2387-2406 2011), and an open question of G allo and P elinovsky (J Math Anal

  15. Incremental expansions for the ground-state energy of the two-dimensional Hubbard model

    SciTech Connect

    Malek, J.; Flach, S.; Kladko, K.

    1999-02-01

    A generalization of Faddeev{close_quote}s approach of the three-body problem to the many-body problem leads to the method of increments. This method was recently applied to account for the ground-state properties of Hubbard-Peierls chains [J. Malek, K. Kladko, and S. Flach, JETP Lett. {bold 67}, 1052 (1998)]. Here we generalize this approach to two-dimensional square lattices and explicitly treat the incremental expansion up to third order. Comparing our numerical results with various other approaches (Monte Carlo, cumulant approaches) we show that incremental expansions are very efficient because good accuracy with these approaches is achieved treating lattice segments composed of eight sites only. {copyright} {ital 1999} {ital The American Physical Society}

  16. Theoretical study of the structure and analytic potential energy function for the ground state of the PO2 molecule

    NASA Astrophysics Data System (ADS)

    Zeng, Hui; Zhao, Jun

    2012-07-01

    In this paper, the energy, equilibrium geometry, and harmonic frequency of the ground electronic state of PO2 are computed using the B3LYP, B3P86, CCSD(T), and QCISD(T) methods in conjunction with the 6-311++G(3df, 3pd) and cc-pVTZ basis sets. A comparison between the computational results and the experimental values indicates that the B3P86/6-311++G(3df, 3pd) method can give better energy calculation results for the PO2 molecule. It is shown that the ground state of the PO2 molecule has C2ν symmetry and its ground electronic state is X2A1. The equilibrium parameters of the structure are RP-O = 0.1465 nm, ∠OPO = 134.96°, and the dissociation energy is Ed = 19.218 eV. The bent vibrational frequency ν1 = 386 cm-1, symmetric stretching frequency ν2 = 1095 cm-1, and asymmetric stretching frequency ν3 = 1333 cm-1 are obtained. On the basis of atomic and molecular reaction statics, a reasonable dissociation limit for the ground state of the PO2 molecule is determined. Then the analytic potential energy function of the PO2 molecule is derived using many-body expansion theory. The potential curves correctly reproduce the configurations and the dissociation energy for the PO2 molecule.

  17. Self-, N2-, O2-broadening coefficients and line parameters of HFC-32 for ν7 band and ground state transitions from infrared and microwave spectroscopy

    NASA Astrophysics Data System (ADS)

    Tasinato, Nicola; Turchetto, Arianna; Puzzarini, Cristina; Stoppa, Paolo; Pietropolli Charmet, Andrea; Giorgianni, Santi

    2014-09-01

    Hydrofluorocarbons have been used as replacement gases of chlorofluorocarbons, since the latter have been phased out by the Montreal Protocol due to their environmental hazardous ozone-depleting effects. This is also the case of difluoromethane (CH2F2, HFC-32), which nowadays is widely used in refrigerant mixtures together with CF3CH3, CF3CH2F, and CF3CHF2. Due to its commercial use, in the last years, the atmospheric concentration of HFC-32 has increased significantly. However, this molecule presents strong absorptions within the 8-12 μm atmospheric window, and hence it is a greenhouse gas which contributes to global warming. Although over the years several experimental and theoretical investigations dealt with the spectroscopic properties of CH2F2, up to now pressure broadening coefficients have never been determined. In the present work, the line-by-line parameters of CH2F2 are retrieved for either ground state or ν7 band transitions by means of microwave (MW) and infrared (IR) absorption spectroscopy, respectively. In particular, laboratory experiments are carried out on 9 pure rotational transitions of the ground state and 26 ro-vibrational transitions belonging to the ν7 band lying around 8.2 μm within the atmospheric region. Measurements are carried out at room temperature on self-perturbed CH2F2 as well as on CH2F2 perturbed by N2 and O2. The line shape analysis leads to the first determination of self-, N2-, O2-, and air-broadening coefficients, and also of line intensities (IR). Upon comparison, broadening coefficients of ground state transitions are larger than those of the ν7 band, and no clear dependence on the rotational quantum numbers can be reported. The obtained results represent basic information for the atmospheric modelling of this compound as well as for remote sensing applications.

  18. Method and basis set dependence of anharmonic ground state nuclear wave functions and zero-point energies: application to SSSH.

    PubMed

    Kolmann, Stephen J; Jordan, Meredith J T

    2010-02-07

    One of the largest remaining errors in thermochemical calculations is the determination of the zero-point energy (ZPE). The fully coupled, anharmonic ZPE and ground state nuclear wave function of the SSSH radical are calculated using quantum diffusion Monte Carlo on interpolated potential energy surfaces (PESs) constructed using a variety of method and basis set combinations. The ZPE of SSSH, which is approximately 29 kJ mol(-1) at the CCSD(T)/6-31G* level of theory, has a 4 kJ mol(-1) dependence on the treatment of electron correlation. The anharmonic ZPEs are consistently 0.3 kJ mol(-1) lower in energy than the harmonic ZPEs calculated at the Hartree-Fock and MP2 levels of theory, and 0.7 kJ mol(-1) lower in energy at the CCSD(T)/6-31G* level of theory. Ideally, for sub-kJ mol(-1) thermochemical accuracy, ZPEs should be calculated using correlated methods with as big a basis set as practicable. The ground state nuclear wave function of SSSH also has significant method and basis set dependence. The analysis of the nuclear wave function indicates that SSSH is localized to a single symmetry equivalent global minimum, despite having sufficient ZPE to be delocalized over both minima. As part of this work, modifications to the interpolated PES construction scheme of Collins and co-workers are presented.

  19. Hartree-Fock and Roothaan-Hartree-Fock energies for the ground states of He through Xe

    NASA Astrophysics Data System (ADS)

    Bunge, Carlos F.; Barrientos, José A.; Bunge, Annik Vivier; Cogordan, J. A.

    1992-10-01

    We report a compilation of Roothaan-Hartree-Fock (RHF) wave functions for the ground states of He through Xe, with atomic orbitals expressed in terms of Slater-type functions. Slight increases in the size of the basis set with respect to those used in Clementi and Roetti's tables [At. Data Nucl. Data Tables 14, 177 (1974)] turn out to yield total energies to better than eight figures, reducing between 21 and 2770 times the energy errors in the above tables, and also improving over the previous numerical HF energies computed by Froese Fischer $[-The Hartree-Fock Method for Atoms (Wiley, New York, 1977)]. We also report 10-digit numerical HF energies with different results for Cr, Cu, Nb, Mo, Ru, Rh, Pd, and Ag.

  20. Correlations of Energy Ratios for Collective Nuclear Bands

    NASA Astrophysics Data System (ADS)

    Zamfir, N. V.; Bucurescu, D.; Căta-Danil, G.; Ivaşcu, M.; Mărginean, N.

    2009-01-01

    It is shown that the Mallmann's energy correlations, introduced a long time ago for the ground state bands of the even-even nuclei are, in fact, universal. Various bands in all collective nuclei (even-even, odd-even, and odd-odd) obey the same systematics. This unique, universal behaviour indicates the same spin dependence of the energy of the levels and, consequently, a common structure of all collective bands. Based on the second-order anharmonic vibrator description, parameter-free recurrence relations between energy ratios are deduced. These relations can be used to predict levels of higher spins in various bands.

  1. Correlations of Energy Ratios for Collective Nuclear Bands

    NASA Astrophysics Data System (ADS)

    Zamfir, N. V.; Bucurescu, D.; Căta-Danil, G.; Ivaşcu, M.; Mărginean, N.

    2009-03-01

    It is shown that the Mallmann's energy correlations, introduced a long time ago for the ground state bands of the even-even nuclei are, in fact, universal. Various bands in all collective nuclei (even-even, odd-even, and odd-odd) obey the same systematics. This unique, universal behaviour indicates the same spin dependence of the energy of the levels in all bands in all collective nuclei. Based on a second-order anharmonic vibrator description, parameter-free recurrence relations between energy ratios are deduced. These relations can be used to predict levels of higher spins in various bands.

  2. Effect of Rasbha spin-orbit interaction on the ground state energy of a hydrogenic D{sup 0} complex in a Gaussian quantum dot

    SciTech Connect

    Boda, Aalu Kumar, D. Sanjeev; Chatterjee, Ashok; Mukhopadhyay, Soma

    2015-06-24

    The ground state energy of a hydrogenic D{sup 0} complex trapped in a three-dimensional GaAs quantum dot with Gaussian confinement is calculated variationally incorporating the effect of Rashba spin-orbit interaction. The results are obtained as a function of the quantum dot size and the Rashba spin-orbit interaction. The results show that the Rashba interaction reduces the ground state energy of the system.

  3. Ground state energy of the δ-Bose and Fermi gas at weak coupling from double extrapolation

    NASA Astrophysics Data System (ADS)

    Prolhac, Sylvain

    2017-04-01

    We consider the ground state energy of the Lieb–Liniger gas with δ interaction in the weak coupling regime γ \\to 0 . For bosons with repulsive interaction, previous studies gave the expansion {{e}\\text{B}}≤ft(γ \\right)≃ γ -4{γ3/2}/3π +≤ft(1/6-1/{π2}\\right){γ2} . Using a numerical solution of the Lieb–Liniger integral equation discretized with M points and finite strength γ of the interaction, we obtain very accurate numerics for the next orders after extrapolation on M and γ. The coefficient of {γ5/2} in the expansion is found to be approximately equal to -0.001 587 699 865 505 944 989 29 , accurate within all digits shown. This value is supported by a numerical solution of the Bethe equations with N particles, followed by extrapolation on N and γ. It was identified as ≤ft(3\\zeta (3)/8-1/2\\right)/{π3} by G Lang. The next two coefficients are also guessed from the numerics. For balanced spin 1/2 fermions with attractive interaction, the best result so far for the ground state energy has been {{e}\\text{F}}≤ft(γ \\right)≃ {π2}/12-γ /2+{γ2}/6 . An analogue double extrapolation scheme leads to the value -\\zeta (3)/{π4} for the coefficient of {γ3} .

  4. Ground-state properties of the periodic Anderson model

    NASA Technical Reports Server (NTRS)

    Blankenbecler, R.; Fulco, J. R.; Gill, W.; Scalapino, D. J.

    1987-01-01

    The ground-state energy, hybridization matrix element, local moment, and spin-density correlations of a one-dimensional, finite-chain, periodic, symmetric Anderson model are obtained by numerical simulations and compared with perturbation theory and strong-coupling results. It is found that the local f-electron spins are compensated by correlation with other f-electrons as well as band electrons leading to a nonmagnetic ground state.

  5. Coupled-Cluster in Real Space I: CC2 Ground State Energies using Multi-Resolution Analysis.

    PubMed

    Kottmann, Jakob Siegfried; Bischoff, Florian Andreas

    2017-09-13

    A framework to calculate approximate coupled-cluster CC2 ground-state correlation energies in a multiresolution basis is derived and implemented into the MADNESS library. The CC2 working equations are rederived in first quantization which makes them suitable for real-space methods. The first-quantized equations can be interpreted diagrammatically using the usual diagrams from second quantization with adjusted interpretation rules. Singularities arising form the nuclear and electronic potentials are regularized by explicitly taking the nuclear and electronic cusps into account. The regularized three- and six-dimensional cluster functions are represented directly on a grid. The resulting equations are free of singularities and virtual orbitals, which results into a lower intrinsic scaling of N^3. Correlation energies close to the basis set limit are computed for small molecules. This work is the first step towards CC2 excitation energies in a multiresolution basis.

  6. Accurate Ground-State Energies of Solids and Molecules from Time-Dependent Density-Functional Theory

    NASA Astrophysics Data System (ADS)

    Olsen, Thomas; Thygesen, Kristian S.

    2014-05-01

    We demonstrate that ground-state energies approaching chemical accuracy can be obtained by combining the adiabatic-connection fluctuation-dissipation theorem with time-dependent density-functional theory. The key ingredient is a renormalization scheme, which eliminates the divergence of the correlation hole characteristic of any local kernel. This new class of renormalized kernels gives a significantly better description of the short-range correlations in covalent bonds compared to the random phase approximation (RPA) and yields a fourfold improvement of RPA binding energies in both molecules and solids. We also consider examples of barrier heights in chemical reactions, molecular adsorption, and graphene interacting with metal surfaces, which are three examples where the RPA has been successful. In these cases, the renormalized kernel provides results that are of equal quality or even slightly better than the RPA, with a similar computational cost.

  7. Accurate high level ab initio-based global potential energy surface and dynamics calculations for ground state of CH2(+).

    PubMed

    Li, Y Q; Zhang, P Y; Han, K L

    2015-03-28

    A global many-body expansion potential energy surface is reported for the electronic ground state of CH2 (+) by fitting high level ab initio energies calculated at the multireference configuration interaction level with the aug-cc-pV6Z basis set. The topographical features of the new global potential energy surface are examined in detail and found to be in good agreement with those calculated directly from the raw ab initio energies, as well as previous calculations available in the literature. In turn, in order to validate the potential energy surface, a test theoretical study of the reaction CH(+)(X(1)Σ(+))+H((2)S)→C(+)((2)P)+H2(X(1)Σg (+)) has been carried out with the method of time dependent wavepacket on the title potential energy surface. The total integral cross sections and the rate coefficients have been calculated; the results determined that the new potential energy surface can both be recommended for dynamics studies of any type and as building blocks for constructing the potential energy surfaces of larger C(+)/H containing systems.

  8. Kinetic and electron-electron energies for convex sums of ground state densities with degeneracies and fractional electron number

    SciTech Connect

    Levy, Mel E-mail: mlevy@tulane.edu; Anderson, James S. M.; Zadeh, Farnaz Heidar; Ayers, Paul W. E-mail: mlevy@tulane.edu

    2014-05-14

    Properties of exact density functionals provide useful constraints for the development of new approximate functionals. This paper focuses on convex sums of ground-level densities. It is observed that the electronic kinetic energy of a convex sum of degenerate ground-level densities is equal to the convex sum of the kinetic energies of the individual degenerate densities. (The same type of relationship holds also for the electron-electron repulsion energy.) This extends a known property of the Levy-Valone Ensemble Constrained-Search and the Lieb Legendre-Transform refomulations of the Hohenberg-Kohn functional to the individual components of the functional. Moreover, we observe that the kinetic and electron-repulsion results also apply to densities with fractional electron number (even if there are no degeneracies), and we close with an analogous point-wise property involving the external potential. Examples where different degenerate states have different kinetic energy and electron-nuclear attraction energy are given; consequently, individual components of the ground state electronic energy can change abruptly when the molecular geometry changes. These discontinuities are predicted to be ubiquitous at conical intersections, complicating the development of universally applicable density-functional approximations.

  9. Analytical expressions for partial wave two-body Coulomb transition matrices at ground-state energy

    NASA Astrophysics Data System (ADS)

    Kharchenko, V. F.

    2016-11-01

    Leaning upon the Fock method of the stereographic projection of the three-dimensional momentum space onto the four-dimensional unit sphere the possibility of the analytical solving of the Lippmann-Schwinger integral equation for the partial wave two-body Coulomb transition matrix at the ground bound state energy has been studied. In this case new expressions for the partial p-, d- and f-wave two-body Coulomb transition matrices have been obtained in the simple analytical form. The developed approach can also be extended to determine analytically the partial wave Coulomb transition matrices at the energies of excited bound states.

  10. Double many-body expansion potential energy surface for ground state HSO2.

    PubMed

    Ballester, M Y; Varandas, A J C

    2005-06-07

    A global potential energy surface is reported for the ground electronic state of HSO2 by using the double many-body expansion (DMBE) method. It employs realistic DMBE functions previously reported from accurate ab initio calculations (in some cases, fine tuned to spectroscopic data) for the triatomic fragments, and four-body energy terms that were modelled by fitting novel ab initio FVCAS/AVTZ calculations for the tetratomic system. In some cases, FVCAS/AVDZ energies have been employed after being scaled to FVCAS/AVTZ ones. To assess the role of the dynamical correlation, exploratory single-point Rayleigh-Schrödinger perturbation calculations have also been conducted at one stationary point. All reported calculations are compared with previous ab initio results for the title system. The potential energy surface predicts HOSO to be the most stable configuration, in good agreement with other theoretical data available in the literature. In turn, the HSO2 isomer with H bonded to S is described as a local minimum, which is stable with respect to the H + SO2 dissociation asymptote.

  11. Unification of ground-state aromaticity criteria - structure, electron delocalization, and energy - in light of the quantum chemical topology.

    PubMed

    Badri, Zahra; Foroutan-Nejad, Cina

    2016-04-28

    In the present account we investigate a theoretical link between the bond length, electron sharing, and bond energy within the context of quantum chemical topology theories. The aromatic stabilization energy, ASE, was estimated from this theoretical link without using isodesmic reactions for the first time. The ASE values obtained from our method show a meaningful correlation with the number of electrons contributing to the aromaticity. This theoretical link demonstrates that structural, electronic, and energetic criteria of aromaticity - ground-state aromaticity - belong to the same class and guarantees that they assess the same property as aromaticity. Theory suggests that interatomic exchange-correlation potential, obtained from the theory of Interacting Quantum Atoms (IQA), is linearly connected to the delocalization index of Quantum Theory of Atoms in Molecules (QTAIM) and the bond length through a first order approximation. Our study shows that the relationship between energy, structure and electron sharing marginally deviates from the ideal linear form expected from the first order approximation. The observed deviation from linearity was attributed to a different contribution of exchange-correlation to the bond energy for the σ- and π-frameworks. Finally, we proposed two-dimensional energy-structure-based aromaticity indices in analogy to the electron sharing indices of aromaticity.

  12. Effects of low-lying excitations on ground-state energy and energy gap of the Sherrington-Kirkpatrick model in a transverse field

    NASA Astrophysics Data System (ADS)

    Koh, Yang Wei

    2016-04-01

    We present an extensive numerical study of the Sherrington-Kirkpatrick model in a transverse field. Recent numerical studies of quantum spin glasses have focused on exact diagonalization of the full Hamiltonian for small systems (≈20 spins). However, such exact numerical treatments are difficult to apply on larger systems. We propose making an approximation by using only a subspace of the full Hilbert space spanned by low-lying excitations consisting of one-spin-flipped and two-spin-flipped states. The approximation procedure is carried out within the theoretical framework of the Hartree-Fock approximation and configuration interaction. Although not exact, our approach allows us to study larger system sizes comparable to that achievable by state-of-the-art quantum Monte Carlo simulations. We calculate two quantities of interest due to recent advances in quantum annealing, the ground-state energy and the energy gap between the ground and first excited states. For the energy gap, we derive a formula that enables it to be calculated using just the ground-state wave function, thereby circumventing the need to diagonalize the Hamiltonian. We calculate the scalings of the energy gap and the leading correction to the extensive part of the ground-state energy with system size, which are difficult to obtain with current methods.

  13. Nonadiabatic couplings in low-energy collisions of hydrogen ground-state atoms

    SciTech Connect

    Wolniewicz, L.

    2003-10-01

    The effect of nonadiabatic couplings on low-energy s-wave scattering of two hydrogen atoms is investigated. Coupling matrix elements are computed in a wide range of internuclear distances. The resulting scattering equations are numerically unstable and therefore are integrated only approximately. Computations are performed for H, D, and T atoms. The phase shifts in the zero velocity limit are inversely proportional to the nuclear reduced mass {delta}{sub 0}{approx_equal}0.392/{mu}. This leads to infinite scattering lengths.

  14. Constructive approach to the ground-state energy of a hard-core square-well fermion system

    SciTech Connect

    Baker, G.A. Jr.

    1984-09-01

    I am looking at the old problem of the ground-state energy of quantum many-Fermion systems. My tools will be a version of perturbation theory. It is plain that the ordinary, low-density rearrangement can not be used directly to compute the saturation energy and density of a system for which the two-body potential has a strong repulsive core and an attractive portion beyond the core, because the path of continuation from low-density to saturation density passes through the two-phase (vacuum, liquid) region. Likewise it is difficult to supply an expansion directly in lambda for fixed rho (density) because of the difficulty of the strong repulsive core and the tediousness of the calculations. My approach here is to expand the energy in a double series in k/sub F/, the Fermi momentum, and lambda, the strength of the attractive part of the potential. The plan is then to sum up, by the Pade method or a generalization of it, the k/sub F/ expansions of the coefficients of each power of lambda into a function of k/sub F/. The coefficient of lambda/sup 0/ is just the repulsive-core energy itself.

  15. An efficient fragment-based approach for predicting the ground-state energies and structures of large molecules.

    PubMed

    Li, Shuhua; Li, Wei; Fang, Tao

    2005-05-18

    An efficient fragment-based approach for predicting the ground-state energies and structures of large molecules at the Hartree-Fock (HF) and post-HF levels is described. The physical foundation of this approach is attributed to the "quantum locality" of the electron correlation energy and the HF total energy, which is revealed by a new energy decomposition analysis of the HF total energy proposed in this work. This approach is based on the molecular fractionation with conjugated caps (MFCC) scheme (Zhang, D. W.; Zhang, J. Z. H. J. Chem. Phys. 2003, 119, 3599), by which a macromolecule is partitioned into various capped fragments and conjugated caps formed by two adjacent caps. We find that the MFCC scheme, if corrected by the interaction between non-neighboring fragments, can be used to predict the total energy of large molecules only from energy calculations on a series of small subsystems. The approach, named as energy-corrected MFCC (EC-MFCC), computationally achieves linear scaling with the molecular size. Our test calculations on a broad range of medium- and large molecules demonstrate that this approach is able to reproduce the conventional HF and second-order Moller-Plesset perturbation theory (MP2) energies within a few millihartree in most cases. With the EC-MFCC optimization algorithm described in this work, we have obtained the optimized structures of long oligomers of trans-polyacetylene and BN nanotubes with up to about 400 atoms, which are beyond the reach of traditional computational methods. In addition, the EC-MFCC approach is also applied to estimate the heats of formation for a series of organic compounds. This approach provides an appealing approach alternative to the traditional additivity rules based on either bond or group contributions for the estimation of thermochemical properties.

  16. Ground state structure of high-energy-density polymeric carbon monoxide

    NASA Astrophysics Data System (ADS)

    Xia, Kang; Sun, Jian; Pickard, Chris J.; Klug, Dennis D.; Needs, Richard J.

    2017-04-01

    Crystal structure prediction methods and first-principles calculations have been used to explore low-energy structures of carbon monoxide (CO). Contrary to the standard wisdom, the most stable structure of CO at ambient pressure was found to be a polymeric structure of P n a 21 symmetry rather than a molecular solid. This phase is formed from six-membered (four carbon + two oxygen) rings connected by C=C double bonds with two double-bonded oxygen atoms attached to each ring. Interestingly, the polymeric P n a 21 phase of CO has a much higher energy density than trinitrotoluene (TNT). On compression to about 7 GPa, P n a 21 is found to transform into another chainlike phase of C c symmetry which has similar ring units to P n a 21 . On compression to 12 GPa, it is energetically favorable for CO to polymerize into a purely single bonded C m c a phase, which is stable over a wide pressure range and transforms into the previously known C m c m phase at around 100 GPa. Thermodynamic stability of these structures was verified using calculations with different density functionals, including hybrid and van der Waals corrected functionals.

  17. Energy-localization-enhanced ground-state cooling of a mechanical resonator from room temperature in optomechanics using a gain cavity

    NASA Astrophysics Data System (ADS)

    Liu, Yu-Long; Liu, Yu-xi

    2017-08-01

    When a gain system is coupled to a loss system, the energy usually flows from the gain system to the loss one. We here present a counterintuitive theory for the ground-state cooling of a mechanical resonator in an optomechanical system via a gain cavity. The energy flows first from the mechanical resonator into the loss cavity and then into the gain cavity and finally localizes there. The energy localization in the gain cavity dramatically enhances the cooling rate of the mechanical resonator. Moreover, we show that an unconventional optical spring effect, e.g., a giant frequency shift and optically induced damping of the mechanical resonator, can be realized. Those feature a precooling-free ground-state cooling, i.e., the mechanical resonator in thermal excitation at room temperature can directly be cooled to its ground state. This cooling approach has potential application in fundamental tests of quantum physics without complicated cryogenic setups.

  18. Potential energy surfaces in atomic structure: The role of Coulomb correlation in the ground state of helium

    NASA Astrophysics Data System (ADS)

    Salas, L. D.; Arce, J. C.

    2017-02-01

    For the S states of two-electron atoms, we introduce an exact and unique factorization of the internal eigenfunction in terms of a marginal amplitude, which depends functionally on the electron-nucleus distances r1 and r2, and a conditional amplitude, which depends functionally on the interelectronic distance r12 and parametrically on r1 and r2. Applying the variational principle, we derive pseudoeigenvalue equations for these two amplitudes, which cast the internal Schrödinger equation in a form akin to the Born-Oppenheimer separation of nuclear and electronic degrees of freedom in molecules. The marginal equation involves an effective radial Hamiltonian, which contains a nonadiabatic potential energy surface that takes into account all interparticle correlations in an averaged way, and whose unique eigenvalue is the internal energy. At each point (r1,r2) , such surface is, in turn, the unique eigenvalue in the conditional equation. Employing the ground state of He as prototype, we show that the nonadiabatic potential energy surface affords a molecularlike interpretation of the structure of the atom, and aids in the analysis of energetic and spatial aspects of the Coulomb correlation, in particular correlation-induced symmetry breaking and quantum phase transition.

  19. Potential Energy Curves and Transport Properties for the Interaction of He with Other Ground-state Atoms

    NASA Technical Reports Server (NTRS)

    Partridge, Harry; Stallcop, James R.; Levin, Eugene; Arnold, Jim (Technical Monitor)

    2001-01-01

    The interactions of a He atom with a heavier atom are examined for 26 different elements, which are consecutive members selected from three rows (Li - Ne, Na - Ar, and K,Ca, Ga - Kr) and column 12 (Zn,Cd) of the periodic table. Interaction energies are determined wing high-quality ab initio calculations for the states of the molecule that would be formed from each pair of atoms in their ground states. Potential energies are tabulated for a broad range of Interatomic separation distances. The results show, for example, that the energy of an alkali interaction at small separations is nearly the same as that of a rare-gas interaction with the same electron configuration for the dosed shells. Furthermore, the repulsive-range parameter for this region is very short compared to its length for the repulsion dominated by the alkali-valence electron at large separations (beyond about 3-4 a(sub 0)). The potential energies in the region of the van der Waals minimum agree well with the most accurate results available. The ab initio energies are applied to calculate scattering cross sections and obtain the collision integrals that are needed to determine transport properties to second order. The theoretical values of Li-He total scattering cross sections and the rare-gas atom-He transport properties agree well (to within about 1%) with the corresponding measured data. Effective potential energies are constructed from the ab initio energies; the results have been shown to reproduce known transport data and can be readily applied to predict unknown transport properties for like-atom interactions.

  20. Ground-state energy and entropy of the two-dimensional Edwards-Anderson spin-glass model with different bond distributions

    NASA Astrophysics Data System (ADS)

    Perez-Morelo, D. J.; Ramirez-Pastor, A. J.; Romá, F.

    2012-02-01

    We study the two-dimensional Edwards-Anderson spin-glass model using a parallel tempering Monte Carlo algorithm. The ground-state energy and entropy are calculated for different bond distributions. In particular, the entropy is obtained by using a thermodynamic integration technique and an appropriate reference state, which is determined with the method of high-temperature expansion. This strategy provides accurate values of this quantity for finite-size lattices. By extrapolating to the thermodynamic limit, the ground-state energy and entropy of the different versions of the spin-glass model are determined.

  1. A diabatic parameterization of the twofold ground state potential energy surface of the H2O-OH molecular complex

    NASA Astrophysics Data System (ADS)

    Galbis, E.; Giglio, E.; Gervais, B.

    2013-10-01

    We present a matrix functional form to fit the nearly degenerated potential energy surface of the H2O-OH molecular complex. The functional form is based on second order perturbation theory, which allows us to define two diabatic states coupled together in the field of the surrounding water molecules. The fit reproduces faithfully the fine details of the potential energy surface (PES) like the crossings and the shallow barrier between the main and secondary minima. The explicit dependence of the model on polarization ensures its transferability to systems made of several water molecules. The potential is used to investigate the structural properties of the OH radical in solution by Monte Carlo simulation. The twin surface fit shows that the second PES is shifted above the ground state by typically 1600 cm-1 for the configurations explored at a temperature of 300 K and a density of 1.0 g/cm3. The second PES has thus little influence on the structuring of water around the OH radical at such a temperature and density. Our study confirms that under these thermodynamic conditions, OH is a weak hydrogen acceptor.

  2. Ground-state energies and charge radii of medium-mass nuclei in the unitary-model-operator approach

    NASA Astrophysics Data System (ADS)

    Miyagi, Takayuki; Abe, Takashi; Okamoto, Ryoji; Otsuka, Takaharu

    2014-09-01

    In nuclear structure theory, one of the most fundamental problems is to understand the nuclear structure based on nuclear forces. This attempt has been enabled due to the progress of the computational power and nuclear many-body approaches. However, it is difficult to apply the first-principle methods to medium-mass region, because calculations demand the huge model space as increasing the number of nucleons. The unitary-model-operator approach (UMOA) is one of the methods which can be applied to medium-mass nuclei. The essential point of the UMOA is to construct the effective Hamiltonian which does not induce the two-particle-two-hole excitations. A many-body problem is reduced to the two-body subsystem problem in an entire many-body system with the two-body effective interaction and one-body potential determined self-consistently. In this presentation, we will report the numerical results of ground-state energies and charge radii of 16O, 40Ca, and 56Ni in the UMOA, and discuss the saturation property by comparing our results with those in the other many-body methods and also experimental data. In nuclear structure theory, one of the most fundamental problems is to understand the nuclear structure based on nuclear forces. This attempt has been enabled due to the progress of the computational power and nuclear many-body approaches. However, it is difficult to apply the first-principle methods to medium-mass region, because calculations demand the huge model space as increasing the number of nucleons. The unitary-model-operator approach (UMOA) is one of the methods which can be applied to medium-mass nuclei. The essential point of the UMOA is to construct the effective Hamiltonian which does not induce the two-particle-two-hole excitations. A many-body problem is reduced to the two-body subsystem problem in an entire many-body system with the two-body effective interaction and one-body potential determined self-consistently. In this presentation, we will report the

  3. Quantum-Merlin-Arthur-complete translationally invariant Hamiltonian problem and the complexity of finding ground-state energies in physical systems

    NASA Astrophysics Data System (ADS)

    Kay, Alastair

    2007-09-01

    Here we present a problem related to the local Hamiltonian problem (identifying whether the ground-state energy falls within one of two ranges) which is restricted to being translationally invariant. We prove that for Hamiltonians with a fixed local dimension and O(log(N)) -body local terms, or local dimension N and two-body terms, there are instances where finding the ground-state energy is quantum-Merlin-Arthur-complete and simulating the dynamics is BQP-complete (BQP denotes “bounded error, quantum polynomial time”). We discuss the implications for the computational complexity of finding ground states of these systems and hence for any classical approximation techniques that one could apply including density-matrix renormalization group, matrix product states, and multiscale entanglement renormalization ansatz. One important example is a one-dimensional lattice of bosons with nearest-neighbor hopping at constant filling fraction—i.e., a generalization of the Bose-Hubbard model.

  4. Collision induced broadening of ν1 band and ground state spectral lines of sulfur dioxide perturbed by N2 and O2

    NASA Astrophysics Data System (ADS)

    Ceselin, Giorgia; Tasinato, Nicola; Puzzarini, Cristina; Charmet, Andrea Pietropolli; Stoppa, Paolo; Giorgianni, Santi

    2017-09-01

    To monitor the constituents and trace pollutants of Earth atmosphere and understand its evolution, accurate spectroscopic parameters are fundamental information. SO2 is produced by both natural and anthropogenic sources and it is one of the principal causes of acid rains as well as an important component of fine aerosol particles, once oxidized to sulfate. The present work aims at determining SO2 broadening parameters using N2 and O2 as atmospherically relevant damping gases. Measurements are carried out in the infrared (IR) and mm-/sub-mm wave regions, around 8.8 μm and in the 104 GHz-1.1 THz interval, respectively. IR ro-vibrational transitions are recorded by using a tunable diode laser spectrometer, whereas the microwave spectra are recorded by using a frequency-modulated millimeter-/submillimeter-wave spectrometer. SO2-N2 and SO2-O2 collisional cross sections are retrieved for several ν1 band ro-vibrational transitions of 32S16O2, for some transitions belonging to either ν1 + ν2 - ν2 of 32S16O2 or ν1 of 34S16O2 as well as for about 20 pure rotational transitions in the vibrational ground state of the main isotopic species. From N2- and O2- broadening coefficients the broadening parameters of SO2 in air are derived. The work is completed with the study of the dependence of foreign broadening coefficients on the rotational quantum numbers.

  5. Ground-state splitting of ultrashallow thermal donors with negative central-cell corrections in silicon

    NASA Astrophysics Data System (ADS)

    Hara, Akito; Awano, Teruyoshi

    2017-06-01

    Ultrashallow thermal donors (USTDs), which consist of light element impurities such as carbon, hydrogen, and oxygen, have been found in Czochralski silicon (CZ Si) crystals. To the best of our knowledge, these are the shallowest hydrogen-like donors with negative central-cell corrections in Si. We observed the ground-state splitting of USTDs by far-infrared optical absorption at different temperatures. The upper ground-state levels are approximately 4 meV higher than the ground-state levels. This energy level splitting is also consistent with that obtained by thermal excitation from the ground state to the upper ground state. This is direct evidence that the wave function of the USTD ground state is made up of a linear combination of conduction band minimums.

  6. Confirmation using Monte Carlo ground-state energies of the instability of free planar films of liquid 4He at T=0 K

    NASA Astrophysics Data System (ADS)

    Szybisz, Leszek

    1998-07-01

    The stability of free slabs of liquid 4He at T=0 K is studied by examining ground-state energies computed with Monte Carlo techniques. A stability condition derived by imposing a positive areal isothermal compressibility is applied. It is shown that Monte Carlo data clearly indicate that all finite films are unstable supporting the finding of previous investigations based on the analysis of values obtained from self-consistent microscopic calculations.

  7. Detecting ground-state degeneracy in many-body systems through qubit decoherence

    NASA Astrophysics Data System (ADS)

    Cui, Hai-Tao; Yi, Xue-Xi

    2017-02-01

    By coupling with a qubit, we demonstrate that qubit decoherence can unambiguously detect the occurrence of ground-state degeneracy in many-body systems. We first demonstrate universality using the two-band model. Consequently, several exemplifications, focused on topological condensed matter systems in one, two, and three dimensions, are presented to validate our proposal. The key point is that qubit decoherence varies significantly when energy bands touch each other at the Fermi surface. In addition, it can partially reflect the degeneracy inside the band. This feature implies that qubit decoherence can be used for reliable diagnosis of ground-state degeneracy.

  8. On the ground state of metallic hydrogen

    NASA Technical Reports Server (NTRS)

    Chakravarty, S.; Ashcroft, N. W.

    1978-01-01

    A proposed liquid ground state of metallic hydrogen at zero temperature is explored and a variational upper bound to the ground state energy is calculated. The possibility that the metallic hydrogen is a liquid around the metastable point (rs = 1.64) cannot be ruled out. This conclusion crucially hinges on the contribution to the energy arising from the third order in the electron-proton interaction which is shown here to be more significant in the liquid phase than in crystals.

  9. Symmetry breaking in cationic polymethine dyes, part 1: Ground state potential energy surfaces and solvent effects on electronic spectra of streptocyanines

    NASA Astrophysics Data System (ADS)

    Iordanov, Tzvetelin D.; Davis, Jesse L.; Masunov, Artëm E.; Levenson, Andrew; Przhonska, Olga V.; Kachkovski, Alexei D.

    Charge localization and dynamics in conjugated organic molecules, as well as their spectral signatures are of great importance for photonic and photovoltaic applications. Intramolecular charge delocalization in polymethine dyes occurs through π-conjugated bridges and contributes to the appearance of low-energy excited states that strongly influence their linear and nonlinear optical (NLO) properties. When the chain length in symmetrical cations exceeds the characteristic size of the soliton, the positive charge may localize at one of the terminal groups of the molecule and induce symmetry breaking of both the electron density distribution and molecular geometry. This charge localization is coupled with molecular vibrations and solvent effects. We investigated the mechanism of symmetry breaking in a series of cationic streptocyanines with different conjugated chain length and qualitatively predicted their electronic absorption spectra. This class of organic molecules is chosen as a model system to develop methodology which can subsequently be used to evaluate more complicated compounds for NLO applications. Our calculations show that the minimum number of vinylene groups in the conjugated chain necessary to break the symmetry of streptocyanines is eight in the gas phase and six in cyclohexane. We constructed the ground state potential energy surface (PES) in two dimensions using symmetry breaking and symmetry adapted coordinates. These were defined as the difference and the sum of the two central carbon-carbon bonds, respectively. This PES was found to have two equivalent minima for systems with symmetry breaking. The energy barrier between these two minima was estimated in the gas phase and in solution, which was taken into account by the polarizable continuum model. Charge localization in each minimum was found to be asymmetric. It is additionally stabilized by the solvent reaction field, which increases the energy barrier. The electronic absorption spectrum in

  10. Photodissociation of CS2 in the vacuum ultraviolet - Determination of bond dissociation energy from the lowest vibrational level of the ground state CS2.

    NASA Technical Reports Server (NTRS)

    Okabe, H.

    1972-01-01

    Photolysis in the vacuum ultraviolet results almost exclusively in the production of S(super-3)P atoms, which is in apparent violation of spin conservation. The threshold energy of incident photons required to produce fluorescence was used to calculate the bond dissociation energy (from the lowest vibrational level of the ground state), and the result agrees with the value previously derived from the photoionization of CS2. The fluorescence excitation spectrum shows peaks corresponding to Rydberg series I and II, indicating that the observed photodissociation of CS2 in the vacuum ultraviolet is mainly the result of predissociation from Rydberg states. The absorption coefficient of CS2 was measured in the region of 1200 to 1400 A.

  11. Application of the MP2/CA results in comparative studies of semi-empirical ground-state energies of large atoms

    NASA Astrophysics Data System (ADS)

    Slupski, Romuald; Nowakowski, Krzysztof

    2003-11-01

    To study the usefulness of second-order Moller-Plesset (MP2) correlation energies for ground states of closed-shell atoms (referred to as MP2/CA energies) in estimations of the total correlation energies of larger closed-shell atoms, we have considered atoms and ions containing from 10 to 86 electrons. First, it is demonstrated that for N-electron systems, 10<=N<=18, the MP2/CA energies provide very good approximations to the very accurate estimates of atomic correlation energies by Chakravorty and Davidson. Next, for systems with 10<=N<=54 comparisons are made with the semiempirical energies obtained when using the models by Charkravorty and Clementi as well as by Clementi and Corongiu. Finally, for atoms with 10<=N<=86 the MP2/CA energies are employed for comparison with DFT energies recently obtained by Andrae et al. The MP2/CA results have proven to provide reasonable estimates to the total correlation energies in all the cases considered.

  12. Accurate high level ab initio-based global potential energy surface and dynamics calculations for ground state of CH{sub 2}{sup +}

    SciTech Connect

    Li, Y. Q.; Zhang, P. Y.; Han, K. L.

    2015-03-28

    A global many-body expansion potential energy surface is reported for the electronic ground state of CH{sub 2}{sup +} by fitting high level ab initio energies calculated at the multireference configuration interaction level with the aug-cc-pV6Z basis set. The topographical features of the new global potential energy surface are examined in detail and found to be in good agreement with those calculated directly from the raw ab initio energies, as well as previous calculations available in the literature. In turn, in order to validate the potential energy surface, a test theoretical study of the reaction CH{sup +}(X{sup 1}Σ{sup +})+H({sup 2}S)→C{sup +}({sup 2}P)+H{sub 2}(X{sup 1}Σ{sub g}{sup +}) has been carried out with the method of time dependent wavepacket on the title potential energy surface. The total integral cross sections and the rate coefficients have been calculated; the results determined that the new potential energy surface can both be recommended for dynamics studies of any type and as building blocks for constructing the potential energy surfaces of larger C{sup +}/H containing systems.

  13. Dependence of the ground-state transition energy versus optical pumping in GaAsSb/InGaAs/GaAs heterostructures

    SciTech Connect

    Morozov, S. V.; Kryzhkov, D. I. Aleshkin, V. Ya.; Yablonsky, A. N.; Krasilnik, Z. F.; Zvonkov, B. N.; Vikhrova, O. V.

    2014-01-13

    In this work, we report on the time-resolved photoluminescence studies of a double quantum well In{sub 0.2}Ga{sub 0.8}As/GaAs{sub 0.8}Sb{sub 0.2}/GaAs heterostructure which, in contrast to the GaAsSb/GaAs structures, is expected to provide effective confinement of electrons due to additional InGaAs layer. The studies at 4.2 K have revealed a complicated nonmonotonic dependence of the ground-state transition energy on the concentration of nonequilibrium charge carriers in the quantum well. The effect observed in this work is important in terms of creating sources of radiation, including stimulated emission, on the basis of InGaAs/GaAsSb/GaAs structures.

  14. Single-sheeted double many-body expansion potential energy surface for ground-state ClO2.

    PubMed

    Teixeira, O B M; Mota, V C; Garcia de la Vega, J M; Varandas, A J C

    2014-07-03

    A global single-sheeted double many-body expansion potential energy surface is reported for the ground electronic state of ClO2. The potential energy surface is obtained by fitting 3200 energy points that map all atom-diatom dissociation channels as well as all relevant stationary points, including the well-known OClO and ClOO structures. The ab initio calculations are obtained at the multireference configuration interaction level of theory, employing the cc-pVXZ (X = D, T) Dunning basis sets, and then extrapolated to the complete basis set limit with the generalized uniform singlet- and triplet-pair protocol. The topographical features of the novel global potential energy surface are examined in detail.

  15. Effect of molecular-orbital rotations on ground-state energies in the parametric two-electron reduced density matrix method.

    PubMed

    Sand, Andrew M; Mazziotti, David A

    2013-06-28

    Different sets of molecular orbitals and the rotations connecting them are of great significance in molecular electronic structure. Most electron correlation methods depend on a reference wave function that separates the orbitals into occupied and unoccupied spaces. Energies and properties from these methods depend upon rotations between the spaces. Some electronic structure methods, such as modified coupled electron pair approximations and the recently developed parametric two-electron reduced density matrix (2-RDM) methods [D. A. Mazziotti, Phys. Rev. Lett. 101, 253002 (2008)], also depend upon rotations between occupied orbitals and rotations between unoccupied orbitals. In this paper, we explore the sensitivity of the ground-state energies from the parametric 2-RDM method to rotations within the occupied space and within the unoccupied space. We discuss the theoretical origin of the rotational dependence and provide computational examples at both equilibrium and non-equilibrium geometries. We also study the effect of these rotations on the size extensivity of the parametric 2-RDM method. Computations show that the orbital rotations have a small effect upon the parametric 2-RDM energies in comparison to the energy differences observed between methodologies such as coupled cluster and parametric 2-RDM. Furthermore, while the 2-RDM method is rigorously size extensive in a local molecular orbital basis set, calculations reveal negligible deviations in nonlocal molecular orbital basis sets such as those from canonical Hartree-Fock calculations.

  16. Measurement of Charge Transfer Rate Coefficient Between Ground-State N(2+) Ion and He at Electron-Volt Energies

    NASA Technical Reports Server (NTRS)

    Fang, Z.; Kwong, Victor H. S.

    1997-01-01

    The charge transfer rate coefficient for the reaction N(2+)(2p(sup 2)P(sup 0)) + He yields products is measured by recording the time dependence of the N(2+) ions stored in an ion trap. A cylindrical radio-frequency ion trap was used to store N(2+) ions produced by laser ablation of a solid titanium nitride target. The decay of the ion signals was analyzed by single exponential least-squares fits to the data. The measured rate coefficient is 8.67(0.76) x 10(exp -11)sq cm/s. The N(2+) ions were at a mean energy of 2.7 eV while He gas was at room temperature, corresponding to an equivalent temperature of 3.9 x 10(exp 3) K. The measured value is in good agreement with a recent calculation.

  17. Resonant Enhancement of Ground State H2+ Formation in Low Energy Charge Transfer between Protons and H2

    NASA Astrophysics Data System (ADS)

    Andrianarijaona, V. M.; King, J. G.; Martin, M. F.; de Ruette, N.; Urbain, X.

    2013-05-01

    We investigated the charge transfer (CT) from an H2 or D2 target to various fast atomic/molecular ions for a wide span of collision energies in the laboratory frame (eV to keV). Vibrationally resolved cross sections have been obtained on a relative scale, by dissociative charge transfer of the product H2+ ions with potassium atoms, and 3-D imaging of the fragments. An absolute value of the total CT cross section has been inferred from the measured ratio of the CT yield for protons and H2+, combined with the recommended H2+ + H2 cross section (ORNL). Our results on the (H2, H+) system benchmark state-to-state calculations at 10eV and above (Phys. Rev. A 75 032703, 2007 and J. Phys. B 42, 105207 2009). In particular, they confirm the vibrational excitation mechanism responsible for the resonance at 50eV, characterized by a dominant population of the ground vibrational state of H2++. The spectra for the isotopic system (D2, H+) will be also presented along with the results of CT performed with H2++ and D2+ projectiles. Research supported by the Fund for Scientific Research - FNRS through IISN Grant No. 4.4504.10, and the National Science Foundation through Grant No. PHY-106887.

  18. Charge Transfer Between Ground-State N(2+) and H2, N2, and CO at Electron-Volt Energies

    NASA Technical Reports Server (NTRS)

    Fang, Z.; Kwong, Victor H. S.

    1997-01-01

    The charge-transfer rate coefficients for reactions of N(2+)(2 S(sup 2)2p(sup 2)P(sup 0)) with H2, N2, and CO are measured using ion storage. A cylindrical rf ion trap was used to store N(2+) ions produced by laser ablation of a solid titanium nitride target. The rate coefficients were derived from the decay rate of the ion signal. The rate coefficients for the above three reactions are 3.38(0.35) x 10(exp -11)sq sm/s at T(sub equiv.)=2.9 x 10(exp 3) K, 2.10(0.18) x 10(exp -9)sq sm/s at T(sub equiv.) = 1.3 x 10(exp 4) K, and 3.37(0.29) x 10(exp -9)sq cm/s at T(sub equiv.) = 1.3 x 10(exp 4) K, respectively. No theoretical or other experimental values are available at this energy range.

  19. Full dimensional potential energy surface for the ground state of H{sub 4}{sup +} system based on triatomic-in-molecules formalism

    SciTech Connect

    Sanz-Sanz, Cristina E-mail: cristina.sanz@gmail.com; Roncero, Octavio; Paniagua, Miguel; Aguado, Alfredo

    2013-11-14

    In this work, we present a global potential energy surface for the ground electronic state of the H{sub 4}{sup +} based on ab initio calculations. The final fit is based on triatomics-in-molecules (TRIM) approximation and it includes extra four-body terms for the better description of some discrepancies found on the TRIM model. The TRIM method itself allows a very accurate description of the asymptotic regions. The global fit uses more than 19 000 multireference configuration interaction ab initio points. The global potential energy surface has an overall root mean square error of 0.013 eV for energies up to 2 eV above the global minimum. This work presents an analysis of the stationary points, reactant and product channels, and crossing between the two lowest TRIM adiabatic states. It is as well included a brief description of the two first excited states of the TRIM matrix, concluding that TRIM method is a very good approximation not only for the ground state but also for at least two of the excited states of H{sub 4}{sup +} system.

  20. Improving the accuracy of ground-state correlation energies within a plane-wave basis set: The electron-hole exchange kernel

    NASA Astrophysics Data System (ADS)

    Dixit, Anant; Ángyán, János G.; Rocca, Dario

    2016-09-01

    A new formalism was recently proposed to improve random phase approximation (RPA) correlation energies by including approximate exchange effects [B. Mussard et al., J. Chem. Theory Comput. 12, 2191 (2016)]. Within this framework, by keeping only the electron-hole contributions to the exchange kernel, two approximations can be obtained: An adiabatic connection analog of the second order screened exchange (AC-SOSEX) and an approximate electron-hole time-dependent Hartree-Fock (eh-TDHF). Here we show how this formalism is suitable for an efficient implementation within the plane-wave basis set. The response functions involved in the AC-SOSEX and eh-TDHF equations can indeed be compactly represented by an auxiliary basis set obtained from the diagonalization of an approximate dielectric matrix. Additionally, the explicit calculation of unoccupied states can be avoided by using density functional perturbation theory techniques and the matrix elements of dynamical response functions can be efficiently computed by applying the Lanczos algorithm. As shown by several applications to reaction energies and weakly bound dimers, the inclusion of the electron-hole kernel significantly improves the accuracy of ground-state correlation energies with respect to RPA and semi-local functionals.

  1. Theoretical study on the ground state of the polar alkali-metal-barium molecules: Potential energy curve and permanent dipole moment

    SciTech Connect

    Gou, Dezhi; Kuang, Xiaoyu Gao, Yufeng; Huo, Dongming

    2015-01-21

    In this paper, we systematically investigate the electronic structure for the {sup 2}Σ{sup +} ground state of the polar alkali-metal-alkaline-earth-metal molecules BaAlk (Alk = Li, Na, K, Rb, and Cs). Potential energy curves and permanent dipole moments (PDMs) are determined using power quantum chemistry complete active space self-consistent field and multi-reference configuration interaction methods. Basic spectroscopic constants are derived from ro-vibrational bound state calculation. From the calculations, it is shown that BaK, BaRb, and BaCs molecules have moderate values of PDM at the equilibrium bond distance (BaK:1.62 D, BaRb:3.32 D, and BaCs:4.02 D). Besides, the equilibrium bond length (4.93 Å and 5.19 Å) and dissociation energy (0.1825 eV and 0.1817 eV) for the BaRb and BaCs are also obtained.

  2. Theoretical study on the ground state of the polar alkali-metal-barium molecules: Potential energy curve and permanent dipole moment

    NASA Astrophysics Data System (ADS)

    Gou, Dezhi; Kuang, Xiaoyu; Gao, Yufeng; Huo, Dongming

    2015-01-01

    In this paper, we systematically investigate the electronic structure for the 2Σ+ ground state of the polar alkali-metal-alkaline-earth-metal molecules BaAlk (Alk = Li, Na, K, Rb, and Cs). Potential energy curves and permanent dipole moments (PDMs) are determined using power quantum chemistry complete active space self-consistent field and multi-reference configuration interaction methods. Basic spectroscopic constants are derived from ro-vibrational bound state calculation. From the calculations, it is shown that BaK, BaRb, and BaCs molecules have moderate values of PDM at the equilibrium bond distance (BaK:1.62 D, BaRb:3.32 D, and BaCs:4.02 D). Besides, the equilibrium bond length (4.93 Å and 5.19 Å) and dissociation energy (0.1825 eV and 0.1817 eV) for the BaRb and BaCs are also obtained.

  3. Coulomb energy differences in analog rotational bands of f7/2-shell nuclei

    NASA Astrophysics Data System (ADS)

    Lenzi, S. M.; Mǎrginean, N.; Napoli, D. R.; Ur, C. A.; Zuker, A. P.; Axiotis, M.; Brandolini, F.; de Angelis, G.; Farnea, E.; Gadea, A.; Martínez-Pinedo, G.; Poves, A.; Sánchez-Solano, J.

    2002-04-01

    Recent experimental and shell model studies of isospin symmetry along the ground state rotational bands in the mirror nuclei 50Fe and 50Cr are presented. This is the heaviest T=1 mirror pair studied so far at high spin. It is shown that the Coulomb energy differences provide a good tool to probe the alignment mechanism at the backbending and that they also give information about the evolution of yrast radii as a function of the angular momentum. .

  4. Coulomb Energy Differences in T = 1 Mirror Rotational Bands in 50Fe and 50Cr

    NASA Astrophysics Data System (ADS)

    Lenzi, S. M.; Mărginean, N.; Napoli, D. R.; Ur, C. A.; Zuker, A. P.; de Angelis, G.; Algora, A.; Axiotis, M.; Bazzacco, D.; Belcari, N.; Bentley, M. A.; Bizzeti, P. G.; Bizzeti-Sona, A.; Brandolini, F.; von Brentano, P.; Bucurescu, D.; Cameron, J. A.; Chandler, C.; de Poli, M.; Dewald, A.; Eberth, H.; Farnea, E.; Gadea, A.; Garces-Narro, J.; Gelletly, W.; Grawe, H.; Isocrate, R.; Joss, D. T.; Kalfas, C. A.; Klug, T.; Lampman, T.; Lunardi, S.; Martínez, T.; Martínez-Pinedo, G.; Menegazzo, R.; Nyberg, J.; Podolyak, Zs.; Poves, A.; Ribas, R. V.; Rossi Alvarez, C.; Rubio, B.; Sánchez-Solano, J.; Spolaore, P.; Steinhardt, T.; Thelen, O.; Tonev, D.; Vitturi, A.; von Oertzen, W.; Weiszflog, M.

    2001-09-01

    Gamma rays from the N = Z-2 nucleus 50Fe have been observed, establishing the rotational ground state band up to the state Jπ = 11+ at 6.994 MeV excitation energy. The experimental Coulomb energy differences, obtained by comparison with the isobaric analog states in its mirror 50Cr, confirm the qualitative interpretation of the backbending patterns in terms of successive alignments of proton and neutron pairs. A quantitative agreement with experiment has been achieved by exact shell model calculations, incorporating the differences in radii along the yrast bands, and properly renormalizing the Coulomb matrix elements in the pf model space.

  5. High-energy tail of the linear momentum distribution in the ground state of hydrogen atoms or hydrogen-like ions

    NASA Astrophysics Data System (ADS)

    Oks, E.

    2001-06-01

    A long-standing dispute concerning the high-energy tail of the linear momentum distribution (HTMD) in the ground state of hydrogen atoms/hydrogen-like ions (GSHA) has been unresolved up to now. A possible resolution of the above dispute might be connected to the problem of the role of singular solutions of quantal equations, which is a fundamental problem in its own right. The paradigm is that, even allowing for finite nuclear sizes, singular solutions of the Dirac equation for the Coulomb problem should be rejected for nuclear charges Z < 1/α≈137. In this paper we break this paradigm. First, we derive a general condition for matching a regular interior solution with a singular exterior solution of the Dirac equation for arbitrary interior and exterior potentials. Then we find explicit forms of several classes of potentials that allow such a match. Finally, we show that, as an outcome, the HTMD for the GSHA acquires terms falling off much slower than the 1/p6-law prescribed by the previously adopted quantal result. Our results open up a unique way to test intimate details of the nuclear structure by performing atomic (rather than nuclear) experiments and calculations.

  6. A Jeziorski-Monkhorst fully uncontracted multi-reference perturbative treatment. I. Principles, second-order versions, and tests on ground state potential energy curves

    NASA Astrophysics Data System (ADS)

    Giner, Emmanuel; Angeli, Celestino; Garniron, Yann; Scemama, Anthony; Malrieu, Jean-Paul

    2017-06-01

    The present paper introduces a new multi-reference perturbation approach developed at second order, based on a Jeziorski-Mokhorst expansion using individual Slater determinants as perturbers. Thanks to this choice of perturbers, an effective Hamiltonian may be built, allowing for the dressing of the Hamiltonian matrix within the reference space, assumed here to be a CAS-CI. Such a formulation accounts then for the coupling between the static and dynamic correlation effects. With our new definition of zeroth-order energies, these two approaches are strictly size-extensive provided that local orbitals are used, as numerically illustrated here and formally demonstrated in the Appendix. Also, the present formalism allows for the factorization of all double excitation operators, just as in internally contracted approaches, strongly reducing the computational cost of these two approaches with respect to other determinant-based perturbation theories. The accuracy of these methods has been investigated on ground-state potential curves up to full dissociation limits for a set of six molecules involving single, double, and triple bond breaking together with an excited state calculation. The spectroscopic constants obtained with the present methods are found to be in very good agreement with the full configuration interaction results. As the present formalism does not use any parameter or numerically unstable operation, the curves obtained with the two methods are smooth all along the dissociation path.

  7. Macroscopic Superpositions as Quantum Ground States

    NASA Astrophysics Data System (ADS)

    Dakić, Borivoje; Radonjić, Milan

    2017-09-01

    We study the question of what kind of a macroscopic superposition can(not) naturally exist as a ground state of some gapped local many-body Hamiltonian. We derive an upper bound on the energy gap of an arbitrary physical Hamiltonian provided that its ground state is a superposition of two well-distinguishable macroscopic "semiclassical" states. For a large class of macroscopic superposition states we show that the gap vanishes in the macroscopic limit. This in turn shows that preparation of such states by simple cooling to the ground state is not experimentally feasible and requires a different strategy. Our approach is very general and can be used to rule out a variety of quantum states, some of which do not even exhibit macroscopic quantum properties. Moreover, our methods and results can be used for addressing quantum marginal related problems.

  8. Numerical Evaluation of 2D Ground States

    NASA Astrophysics Data System (ADS)

    Kolkovska, Natalia

    2016-02-01

    A ground state is defined as the positive radial solution of the multidimensional nonlinear problem \\varepsilon propto k_ bot 1 - ξ with the function f being either f(u) =a|u|p-1u or f(u) =a|u|pu+b|u|2pu. The numerical evaluation of ground states is based on the shooting method applied to an equivalent dynamical system. A combination of fourth order Runge-Kutta method and Hermite extrapolation formula is applied to solving the resulting initial value problem. The efficiency of this procedure is demonstrated in the 1D case, where the maximal difference between the exact and numerical solution is ≈ 10-11 for a discretization step 0:00025. As a major application, we evaluate numerically the critical energy constant. This constant is defined as a functional of the ground state and is used in the study of the 2D Boussinesq equations.

  9. Discrete energy bands in bulk semiconductors

    NASA Astrophysics Data System (ADS)

    Du, Maohua; Shi, Hongliang

    2015-03-01

    Bulk semiconductors typically have continuous valence and conduction bands. Discrete energy levels and bands have been sought after for various applications. For instance, discrete energy levels existing in semiconductor nanocrystals, or quantum does (QDs) have been proposed as a mechanism to suppress hot carrier thermalization and to enhance carrier multiplication in QD solar cells. Impurity bands in the band gap have been introduced for intermediate-band solar cells and for efficient visible light absorption and photocatalysis. In this talk, we show by first principles calculations that, in a multinary compound, a combination of large electronegativity difference between different cations (anions) and large nearest-neighbor distances in cation (anion) sublattices can lead to the splitting of the conduction (valence) band, resulting in several discrete and narrow energy bands separated by large energy gaps. We also discuss applications that may benefit from such electronic structure.

  10. Small and efficient basis sets for the evaluation of accurate interaction energies: aromatic molecule-argon ground-state intermolecular potentials and rovibrational states.

    PubMed

    Cybulski, Hubert; Baranowska-Łączkowska, Angelika; Henriksen, Christian; Fernández, Berta

    2014-11-06

    By evaluating a representative set of CCSD(T) ground state interaction energies for van der Waals dimers formed by aromatic molecules and the argon atom, we test the performance of the polarized basis sets of Sadlej et al. (J. Comput. Chem. 2005, 26, 145; Collect. Czech. Chem. Commun. 1988, 53, 1995) and the augmented polarization-consistent bases of Jensen (J. Chem. Phys. 2002, 117, 9234) in providing accurate intermolecular potentials for the benzene-, naphthalene-, and anthracene-argon complexes. The basis sets are extended by addition of midbond functions. As reference we consider CCSD(T) results obtained with Dunning's bases. For the benzene complex a systematic basis set study resulted in the selection of the (Z)Pol-33211 and the aug-pc-1-33321 bases to obtain the intermolecular potential energy surface. The interaction energy values and the shape of the CCSD(T)/(Z)Pol-33211 calculated potential are very close to the best available CCSD(T)/aug-cc-pVTZ-33211 potential with the former basis set being considerably smaller. The corresponding differences for the CCSD(T)/aug-pc-1-33321 potential are larger. In the case of the naphthalene-argon complex, following a similar study, we selected the (Z)Pol-3322 and aug-pc-1-333221 bases. The potentials show four symmetric absolute minima with energies of -483.2 cm(-1) for the (Z)Pol-3322 and -486.7 cm(-1) for the aug-pc-1-333221 basis set. To further check the performance of the selected basis sets, we evaluate intermolecular bound states of the complexes. The differences between calculated vibrational levels using the CCSD(T)/(Z)Pol-33211 and CCSD(T)/aug-cc-pVTZ-33211 benzene-argon potentials are small and for the lowest energy levels do not exceed 0.70 cm(-1). Such differences are substantially larger for the CCSD(T)/aug-pc-1-33321 calculated potential. For naphthalene-argon, bound state calculations demonstrate that the (Z)Pol-3322 and aug-pc-1-333221 potentials are of similar quality. The results show that these

  11. Dzyaloshinsky-Moriya Interaction and the Ground State in S = 3/2 Perfect Kagome Lattice Antiferromagnet KCr3(OH)6(SO4)2 (Cr-Jarosite) Studied by X-Band and High-Frequency ESR

    NASA Astrophysics Data System (ADS)

    Okubo, Susumu; Nakata, Ryohei; Ikeda, Shohei; Takahashi, Naoki; Sakurai, Takahiro; Zhang, Wei-Min; Ohta, Hitoshi; Shimokawa, Tokuro; Sakai, Tôru; Okuta, Koji; Hara, Shigeo; Sato, Hirohiko

    2017-02-01

    A single-crystal S = 3/2 perfect kagome lattice antiferromagnet, KCr3(OH)6(SO4)2 (Cr-jarosite), has been studied by X-band and high-frequency electron spin resonance (ESR). The g-values perpendicular to the kagome plane (c-axis) and in the plane were determined to be gc = 1.9704 ± 0.0002 and gξ = 1.9720 ± 0.0003, respectively, by high-frequency ESR observed at 265 K. Antiferromagnetic resonances (AFMRs) with an antiferromagnetic gap of 120 GHz were observed at 1.9 K, which is below TN = 4.5 K. The analysis of AFMR modes using the conventional molecular field theory gave dp = 0.27 K and dz = 0.07 K, where dp and dz are in-plane and out-of-plane components of d vector of the Dzyaloshinsky-Moriya (DM) interaction, respectively. On the basis of these results and the exchange interaction of J = 6.15 K estimated by Okuta et al., the ground state of Cr-jarosite was discussed in connection with the Monte Carlo simulation results with classical Heisenberg spins on the kagome lattice by Elhajal et al. Finally, the angular dependence of the linewidth and lineshape observed at 296 K by X-band ESR showed the typical behavior of a two-dimensional Heisenberg antiferromagnet, suggesting the good two-dimensionality of Cr-jarosite.

  12. Energy band alignment at the nanoscale

    NASA Astrophysics Data System (ADS)

    Deuermeier, Jonas; Fortunato, Elvira; Martins, Rodrigo; Klein, Andreas

    2017-01-01

    The energy band alignments at interfaces often determine the electrical functionality of a device. Along with the size reduction into the nanoscale, functional coatings become thinner than a nanometer. With the traditional analysis of the energy band alignment by in situ photoelectron spectroscopy, a critical film thickness is needed to determine the valence band offset. By making use of the Auger parameter, it becomes possible to determine the energy band alignment to coatings, which are only a few Ångström thin. This is demonstrated with experimental data of Cu2O on different kinds of substrate materials.

  13. Ground-state energy, density profiles, and momentum distribution of attractively interacting 1D Fermi gases with hard-wall boundaries: a Monte Carlo study

    NASA Astrophysics Data System (ADS)

    McKenney, J. R.; Shill, C. R.; Porter, W. J.; Drut, J. E.

    2016-11-01

    Motivated by the realization of hard-wall boundary conditions in experiments with ultracold atoms, we investigate the ground-state properties of spin-1/2 fermions with attractive interactions in a one-dimensional box. We use lattice Monte Carlo methods to determine essential quantities like the energy, which we compute as a function of coupling strength and particle number in the regime from few to many particles. Many-fermion systems bound by hard walls display non-trivial density profiles characterized by so-called Friedel oscillations (which are similar to those observed in harmonic traps). In non-interacting systems, the characteristic length scale of the oscillations is set by {(2{k}{{F}})}-1, where {k}{{F}} is the Fermi momentum, while repulsive interactions tend to generate Wigner-crystal oscillations of period {(4{k}{{F}})}-1. Based on the non-interacting result, we find a remarkably simple parametrization of the density profiles of the attractively interacting case, which we generalize to the one-body density matrix. While the total momentum is not a conserved quantity in the presence of hard walls, the magnitude of the momentum does provide a good quantum number. We are therefore able to provide a detailed characterization of the (quasi-)momentum distribution, which displays rather robust discontinuity at the Fermi surface. In addition, we determine the spatially varying on-site density-density correlation, which in turn yields Tan’s contact density and, upon integration, Tan’s contact. As is well known, the latter fully determines the short-range correlations and plays a crucial role in a multitude of equilibrium and non-equilibrium sum rules.

  14. New analytical model for the ozone electronic ground state potential surface and accurate ab initio vibrational predictions at high energy range.

    PubMed

    Tyuterev, Vladimir G; Kochanov, Roman V; Tashkun, Sergey A; Holka, Filip; Szalay, Péter G

    2013-10-07

    An accurate description of the complicated shape of the potential energy surface (PES) and that of the highly excited vibration states is of crucial importance for various unsolved issues in the spectroscopy and dynamics of ozone and remains a challenge for the theory. In this work a new analytical representation is proposed for the PES of the ground electronic state of the ozone molecule in the range covering the main potential well and the transition state towards the dissociation. This model accounts for particular features specific to the ozone PES for large variations of nuclear displacements along the minimum energy path. The impact of the shape of the PES near the transition state (existence of the "reef structure") on vibration energy levels was studied for the first time. The major purpose of this work was to provide accurate theoretical predictions for ozone vibrational band centres at the energy range near the dissociation threshold, which would be helpful for understanding the very complicated high-resolution spectra and its analyses currently in progress. Extended ab initio electronic structure calculations were carried out enabling the determination of the parameters of a minimum energy path PES model resulting in a new set of theoretical vibrational levels of ozone. A comparison with recent high-resolution spectroscopic data on the vibrational levels gives the root-mean-square deviations below 1 cm(-1) for ozone band centres up to 90% of the dissociation energy. New ab initio vibrational predictions represent a significant improvement with respect to all previously available calculations.

  15. An ab initio potential energy surface for the formic acid dimer: zero-point energy, selected anharmonic fundamental energies, and ground-state tunneling splitting calculated in relaxed 1-4-mode subspaces.

    PubMed

    Qu, Chen; Bowman, Joel M

    2016-09-14

    We report a full-dimensional, permutationally invariant potential energy surface (PES) for the cyclic formic acid dimer. This PES is a least-squares fit to 13475 CCSD(T)-F12a/haTZ (VTZ for H and aVTZ for C and O) energies. The energy-weighted, root-mean-square fitting error is 11 cm(-1) and the barrier for the double-proton transfer on the PES is 2848 cm(-1), in good agreement with the directly-calculated ab initio value of 2853 cm(-1). The zero-point vibrational energy of 15 337 ± 7 cm(-1) is obtained from diffusion Monte Carlo calculations. Energies of fundamentals of fifteen modes are calculated using the vibrational self-consistent field and virtual-state configuration interaction method. The ground-state tunneling splitting is computed using a reduced-dimensional Hamiltonian with relaxed potentials. The highest-level, four-mode coupled calculation gives a tunneling splitting of 0.037 cm(-1), which is roughly twice the experimental value. The tunneling splittings of (DCOOH)2 and (DCOOD)2 from one to three mode calculations are, as expected, smaller than that for (HCOOH)2 and consistent with experiment.

  16. Density of States for Warped Energy Bands.

    PubMed

    Mecholsky, Nicholas A; Resca, Lorenzo; Pegg, Ian L; Fornari, Marco

    2016-02-24

    Warping of energy bands can affect the density of states (DOS) in ways that can be large or subtle. Despite their potential for significant practical impacts on materials properties, these effects have not been rigorously demonstrated previously. Here we rectify this using an angular effective mass formalism that we have developed. To clarify the often confusing terminology in this field, "band warping" is precisely defined as pertaining to any multivariate energy function E(k) that does not admit a second-order differential at an isolated critical point in k-space, which we clearly distinguish from band non-parabolicity. We further describe band "corrugation" as a qualitative form of band warping that increasingly deviates from being twice differentiable at an isolated critical point. These features affect the density-of-states and other parameters ascribed to band warping in various ways. We demonstrate these effects, providing explicit calculations of DOS and their effective masses for warped energy dispersions originally derived by Kittel and others. Other physical and mathematical examples are provided to demonstrate fundamental distinctions that must be drawn between DOS contributions that originate from band warping and contributions that derive from band non-parabolicity. For some non-degenerate bands in thermoelectric materials, this may have profound consequences of practical interest.

  17. Ground states of holographic superconductors

    SciTech Connect

    Gubser, Steven S.; Nellore, Abhinav

    2009-11-15

    We investigate the ground states of the Abelian Higgs model in AdS{sub 4} with various choices of parameters, and with no deformations in the ultraviolet other than a chemical potential for the electric charge under the Abelian gauge field. For W-shaped potentials with symmetry-breaking minima, an analysis of infrared asymptotics suggests that the ground state has emergent conformal symmetry in the infrared when the charge of the complex scalar is large enough. But when this charge is too small, the likeliest ground state has Lifshitz-like scaling in the infrared. For positive mass quadratic potentials, Lifshitz-like scaling is the only possible infrared behavior for constant nonzero values of the scalar. The approach to Lifshitz-like scaling is shown in many cases to be oscillatory.

  18. Ground-state Dirac monopole

    SciTech Connect

    Ruokokoski, E.; Moettoenen, M.

    2011-12-15

    We show theoretically that a monopole defect, analogous to the Dirac magnetic monopole, may exist as the ground state of a dilute spin-1 Bose-Einstein condensate. The ground-state monopole is not attached to a single semi-infinite Dirac string but forms a point where the circulation of a single vortex line is reversed. Furthermore, the three-dimensional dynamics of this monopole defect is studied after the magnetic field pinning the monopole is removed and the emergence of antimonopoles is observed. Our scheme is realizable with the current experimental facilities.

  19. Ground-state energy trends in single and multilayered coupled InAs/GaAs quantum dots capped with InGaAs layers: Effects of InGaAs layer thickness and annealing temperature

    SciTech Connect

    Shah, S.; Ghosh, K.; Jejurikar, S.; Mishra, A.; Chakrabarti, S.

    2013-08-01

    Graphical abstract: - Highlights: • Investigation of ground state energy in single and multi-layered InAs/GaAs QD. • Strain reducing layer (InGaAs) prevents the formation of non-radiative. • Strain reducing layer (InGaAs) is responsible for high activation energy. • Significant deviation from the Varshni model, E(T) = E − αT{sup 2}/T + β. - Abstract: Vertically coupled, multilayered InAs/GaAs quantum dots (QDs) covered with thin InGaAs strain-reducing layers (SRLs) are in demand for various technological applications. We investigated low temperature photoluminescence of single and multilayered structures in which the SRL thickness was varied. The SRL layer was responsible for high activation energies. Deviation of experimental data from the Varshni (1967) model, E(T) = E − ∞ T{sup 2}/T + β, suggests that the InAs-layered QDs have properties different from those in bulk material. Anomalous ground-state peak linewidths (FWHM), especially for annealed multilayer structures, were observed. A ground-state peak blue-shift with a broadened linewidth was also observed. Loss of intensity was detected in samples annealed at 800 °C. Presence of SRLs prevents formation of non-radiative centers under high temperature annealing. The results indicate the potential importance of such structures in optoelectronic applications.

  20. Probing the tails of the ground-state energy distribution for the directed polymer in a random medium of dimension d=1,2,3 via a Monte Carlo procedure in the disorder.

    PubMed

    Monthus, Cécile; Garel, Thomas

    2006-11-01

    In order to probe with high precision the tails of the ground-state energy distribution of disordered spin systems, Körner, Katzgraber, and Hartmann have recently proposed an importance-sampling Monte Carlo Markov chain in the disorder. In this paper, we combine their Monte Carlo procedure in the disorder with exact transfer matrix calculations in each sample to measure the negative tail of ground-state energy distribution Pd(E0) for the directed polymer in a random medium of dimension d=1,2,3. In d=1, we check the validity of the algorithm by a direct comparison with the exact result, namely, the Tracy-Widom distribution. In dimensions d=2 and d=3, we measure the negative tail up to ten standard deviations, which correspond to probabilities of order Pd(E0) approximately 10(-22). Our results are in agreement with Zhang's argument, stating that the negative tail exponent eta(d) of the asymptotic behavior lnPd(E0) approximately -|E0|eta(d) as E0-->-infinity is directly related to the fluctuation exponent theta(d) [which governs the fluctuations DeltaE0(L) approximately Ltheta(d) of the ground-state energy E0 for polymers of length L] via the simple formula eta(d)=1/[1-theta(d)]. Throughout the paper, we comment on the similarities and differences with spin glasses.

  1. Ground state structures in ferrofluid monolayers.

    PubMed

    Prokopieva, Taisia A; Danilov, Victor A; Kantorovich, Sofia S; Holm, Christian

    2009-09-01

    A combination of analytical calculations and Monte Carlo simulations is used to find the ground state structures in monodisperse ferrofluid monolayers. Taking into account the magnetic dipole-dipole interaction between all particles in the system we observe different topological structures that are likely to exist at low temperatures. The most energetically favored structures we find are rings, embedded rings, and rings side by side, and we are able to derive analytical expressions for the total energy of these structures. A detailed analysis of embedded rings and rings side by side shows that the interring interactions are negligible. We furthermore find that a single ideal ring is the ground state structure for a ferrofluid monolayer. We compared our theoretical predictions to the results of simulated annealing data and found them to be in excellent agreement.

  2. Energy-banded ions in Saturn's magnetosphere

    NASA Astrophysics Data System (ADS)

    Thomsen, M. F.; Badman, S. V.; Jackman, C. M.; Jia, X.; Kivelson, M. G.; Kurth, W. S.

    2017-05-01

    Using data from the Cassini Plasma Spectrometer ion mass spectrometer, we report the first observation of energy-banded ions at Saturn. Observed near midnight at relatively high magnetic latitudes, the banded ions are dominantly H+, and they occupy the range of energies typically associated with the thermal pickup distribution in the inner magnetosphere (L < 10), but their energies decline monotonically with increasing radial distance (or time or decreasing latitude). Their pitch angle distribution suggests a source at low (or slightly southern) latitudes. The band energies, including their pitch angle dependence, are consistent with a bounce-resonant interaction between thermal H+ ions and the standing wave structure of a field line resonance. There is additional evidence in the pitch angle dependence of the band energies that the particles in each band may have a common time of flight from their most recent interaction with the wave, which may have been at slightly southern latitudes. Thus, while the particles are basically bounce resonant, their energization may be dominated by their most recent encounter with the standing wave.Plain Language SummaryDuring an outbound passage by the Cassini spacecraft through Saturn's inner magnetosphere, ion <span class="hlt">energy</span> distributions were observed that featured discrete flux peaks at regularly spaced <span class="hlt">energies</span>. The peaks persisted over several hours and several Saturn radii of distance away from the planet. We show that these "<span class="hlt">bands</span>" of ions are plausibly the result of an interaction between the Saturnian plasma and standing waves that form along the magnetospheric magnetic field lines. These observations are the first reported evidence that such standing waves may be present in the inner magnetosphere, where they could contribute to the radial transport of Saturn's radiation belt particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..93g5130P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..93g5130P"><span>Two different <span class="hlt">ground</span> <span class="hlt">states</span> in K-intercalated polyacenes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Phan, Quynh T. N.; Heguri, Satoshi; Tamura, Hiroyuki; Nakano, Takehito; Nozue, Yasuo; Tanigaki, Katsumi</p> <p>2016-02-01</p> <p>The electronic states of potassium- (K-) intercalated zigzag-type polycyclic aromatic (PLA) hydrocarbon [polyacene PLAs] Kx(PLAs ) are studied for a series of the four smallest molecules: naphthalene (NN), anthracene (AN), tetracene (TN), and pentacene (PN), focusing on their 1:1 stoichiometric phases. Clear experimental differences are identified between the first group [K1(NN ) and K1(AN ) ] and the second group [K1(TN ) and K1(PN ) ] by magnetic, vibrational, and optical measurements. The first group is categorized as a Mott insulator with an antiferromagnetic <span class="hlt">ground</span> <span class="hlt">state</span> with <span class="hlt">energy</span> of ˜10 meV, whereas the second group is classified as a <span class="hlt">band</span> insulator via dimer formation due to the spin Peierls instability. In the latter system, the first thermally accessible triplet states are located far apart from the singlet <span class="hlt">ground</span> <span class="hlt">states</span> and are not detected by electron spin-resonance spectroscopy until 300 K being very different from what is observed for the hole-doped PN reported earlier. The results give a new systematic understanding on the electronic states of electron-doped PLAs sensitive to the energetic balance among on-site Coulomb repulsion, bandwidth, and the Peierls instability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10124867','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10124867"><span><span class="hlt">Ground</span> <span class="hlt">state</span> searches in fcc intermetallics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wolverton, C.; de Fontaine, D.; Ceder, G.; Dreysse, H.</p> <p>1991-12-01</p> <p>A cluster expansion is used to predict the fcc <span class="hlt">ground</span> <span class="hlt">states</span>, i.e., the stable phases at zero Kelvin as a function of composition, for alloy systems. The intermetallic structures are not assumed, but derived regorously by minimizing the configurational <span class="hlt">energy</span> subject to linear constraints. This <span class="hlt">ground</span> <span class="hlt">state</span> search includes pair and multiplet interactions which spatially extend to fourth nearest neighbor. A large number of these concentration-independent interactions are computed by the method of direct configurational averaging using a linearized-muffin-tin orbital Hamiltonian cast into tight binding form (TB-LMTO). The interactions, derived without the use of any adjustable or experimentally obtained parameters, are compared to those calculated via the generalized perturbation method extention of the coherent potential approximation within the context of a KKR Hamiltonian (KKR-CPA-GPM). Agreement with the KKR-CPA-GPM results is quite excellent, as is the comparison of the <span class="hlt">ground</span> <span class="hlt">state</span> results with the fcc-based portions of the experimentally-determined phase diagrams under consideration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5846564','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5846564"><span><span class="hlt">Ground</span> <span class="hlt">state</span> searches in fcc intermetallics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wolverton, C.; de Fontaine, D. ); Ceder, G. ); Dreysse, H. . Lab. de Physique du Solide)</p> <p>1991-12-01</p> <p>A cluster expansion is used to predict the fcc <span class="hlt">ground</span> <span class="hlt">states</span>, i.e., the stable phases at zero Kelvin as a function of composition, for alloy systems. The intermetallic structures are not assumed, but derived regorously by minimizing the configurational <span class="hlt">energy</span> subject to linear constraints. This <span class="hlt">ground</span> <span class="hlt">state</span> search includes pair and multiplet interactions which spatially extend to fourth nearest neighbor. A large number of these concentration-independent interactions are computed by the method of direct configurational averaging using a linearized-muffin-tin orbital Hamiltonian cast into tight binding form (TB-LMTO). The interactions, derived without the use of any adjustable or experimentally obtained parameters, are compared to those calculated via the generalized perturbation method extention of the coherent potential approximation within the context of a KKR Hamiltonian (KKR-CPA-GPM). Agreement with the KKR-CPA-GPM results is quite excellent, as is the comparison of the <span class="hlt">ground</span> <span class="hlt">state</span> results with the fcc-based portions of the experimentally-determined phase diagrams under consideration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26431178','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26431178"><span>Moving Toward the <span class="hlt">Ground</span> <span class="hlt">State</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kumar, Ishan; Ivanova, Natalia</p> <p>2015-10-01</p> <p>Transferring mouse ESCs to a media supplemented with Mek and Gsk3β inhibitors (2i) provokes marked transcriptional and epigenetic changes, embodying a shift toward <span class="hlt">ground-state</span> pluripotency. In this issue of Cell Stem Cell, Kolodziejczyk et al. (2015) examine population structures of ESCs while Galonska et al. (2015) unravel the mechanisms underlying regulatory network rewiring during 2i-mediated reprogramming. Copyright © 2015 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/951092','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/951092"><span>Eastern <span class="hlt">Band</span> of Cherokee Strategic <span class="hlt">Energy</span> Plan</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Souther Carolina Institute of energy Studies-Robert Leitner</p> <p>2009-01-30</p> <p>The Eastern <span class="hlt">Band</span> of Cherokee Indians was awarded a grant under the U.S. Department of <span class="hlt">Energy</span> Tribal <span class="hlt">Energy</span> Program (TEP) to develop a Tribal Strategic <span class="hlt">Energy</span> Plan (SEP). The grant, awarded under the “First Steps” phase of the TEP, supported the development of a SEP that integrates with the Tribe’s plans for economic development, preservation of natural resources and the environment, and perpetuation of Tribal heritage and culture. The Tribe formed an <span class="hlt">Energy</span> Committee consisting of members from various departments within the Tribal government. This committee, together with its consultant, the South Carolina Institute for <span class="hlt">Energy</span> Studies, performed the following activities: • Develop the Tribe’s <span class="hlt">energy</span> goals and objectives • Establish the Tribe’s current <span class="hlt">energy</span> usage • Identify available renewable <span class="hlt">energy</span> and <span class="hlt">energy</span> efficiency options • Assess the available options versus the goals and objectives • Create an action plan for the selected options</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26382356','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26382356"><span><span class="hlt">Ground</span> <span class="hlt">states</span> of stealthy hyperuniform potentials: I. Entropically favored configurations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, G; Stillinger, F H; Torquato, S</p> <p>2015-08-01</p> <p>Systems of particles interacting with "stealthy" pair potentials have been shown to possess infinitely degenerate disordered hyperuniform classical <span class="hlt">ground</span> <span class="hlt">states</span> with novel physical properties. Previous attempts to sample the infinitely degenerate <span class="hlt">ground</span> <span class="hlt">states</span> used <span class="hlt">energy</span> minimization techniques, introducing algorithmic dependence that is artificial in nature. Recently, an ensemble theory of stealthy hyperuniform <span class="hlt">ground</span> <span class="hlt">states</span> was formulated to predict the structure and thermodynamics that was shown to be in excellent agreement with corresponding computer simulation results in the canonical ensemble (in the zero-temperature limit). In this paper, we provide details and justifications of the simulation procedure, which involves performing molecular dynamics simulations at sufficiently low temperatures and minimizing the <span class="hlt">energy</span> of the snapshots for both the high-density disordered regime, where the theory applies, as well as lower densities. We also use numerical simulations to extend our study to the lower-density regime. We report results for the pair correlation functions, structure factors, and Voronoi cell statistics. In the high-density regime, we verify the theoretical ansatz that stealthy disordered <span class="hlt">ground</span> <span class="hlt">states</span> behave like "pseudo" disordered equilibrium hard-sphere systems in Fourier space. The pair statistics obey certain exact integral conditions with very high accuracy. These results show that as the density decreases from the high-density limit, the disordered <span class="hlt">ground</span> <span class="hlt">states</span> in the canonical ensemble are characterized by an increasing degree of short-range order and eventually the system undergoes a phase transition to crystalline <span class="hlt">ground</span> <span class="hlt">states</span>. In the crystalline regime (low densities), there exist aperiodic structures that are part of the <span class="hlt">ground-state</span> manifold but yet are not entropically favored. We also provide numerical evidence suggesting that different forms of stealthy pair potentials produce the same <span class="hlt">ground-state</span> ensemble in the zero</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvC..92d4303G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvC..92d4303G"><span><span class="hlt">Ground-state</span> properties of rare-earth nuclei in the Nilsson mean-field plus extended-pairing model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guan, Xin; Launey, Kristina D.; Wang, Yin; Pan, Feng; Draayer, Jerry P.</p> <p>2015-10-01</p> <p>The Nilsson mean-field plus extended-pairing model for deformed nuclei is applied to describe the <span class="hlt">ground-state</span> properties of selected rare-earth nuclei. Binding <span class="hlt">energies</span>, even-odd mass differences, <span class="hlt">energies</span> of the first pairing excitation states, and moments of inertia for the <span class="hlt">ground-state</span> <span class="hlt">band</span> of Er-164152, Yb-166154, and Hf-168156 are calculated systematically in the model employing both proton-proton and neutron-neutron pairing interactions. The pairing interaction strengths are determined as a function of the mass number in the isotopic chains. In comparison with the corresponding experimental data, it is shown that pairing interaction is crucial in elucidating the properties of both the <span class="hlt">ground</span> <span class="hlt">state</span> and the first pairing excitation state of these rare-earth nuclei. With model parameters determined by fitting the <span class="hlt">energies</span> of these states, <span class="hlt">ground-state</span> occupation probabilities of valence nucleon pairs with angular momentum J =0 ,1 ,⋯,12 for even-even Yb-162156 are calculated. It is inferred that the occupation probabilities of valence nucleon pairs with even angular momenta are much higher than those of valence nucleon pairs with odd angular momenta. The results clearly indicate that S , D , and G valence nucleon pairs dominate in the <span class="hlt">ground</span> <span class="hlt">state</span> of these nuclei.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARP16002M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARP16002M"><span><span class="hlt">Ground</span> <span class="hlt">state</span> degeneracy, <span class="hlt">energy</span> barriers, and molecular dynamics evidence for two-dimensional disorder in black phosphorus and monochalcogenide monolayers at finite temperature</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mehboudi, Mehrshad; Barraza-Lopez, Salvador; Dorio, Alex M.; Zhu, Wenjuan; van der Zande, Arend; Churchill, Hugh O. H.; Pacheco-Sanjuan, Alejandro A.; Harriss, Edmund O.; Kumar, Pradeep</p> <p></p> <p>Mono-layers of black phosphorus and other two dimensional materials such as mono-layers of SiSe, GeS, GeSe, GeTe, Sns, SnSe, and SnTe with a similar crystalline structure have a four-fold degenerate <span class="hlt">ground</span> <span class="hlt">state</span> that leads to two-dimensional disorder at finite temperature. Disorder happens when neighboring atoms gently re-accommodate bonds beyond a critical temperature. In this talk, the effect of atomic numbers on the transition temperature will be discussed. In addition Car-Parinello molecular dynamics calculations at temperatures 30, 300 and 1000 K were performed on supercells containing more than five hundred atoms and the results from these calculations confirm the transition onto a two-dimensional disordered structure past the critical temperature, which is close to room temperature for many of these compounds. References: M. Mehboudi, A.M. Dorio, W. Zhu, A. van der Zande, H.O.H. Churchill, A.A. Pacheco Sanjuan, E.O.H. Harris, P. Kumar, and S. Barraza-Lopez. arXiv:1510.09153.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5008641','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5008641"><span>Ferromagnetic <span class="hlt">Ground</span> <span class="hlt">States</span> in Face-Centered Cubic Hubbard Clusters</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Souza, T. X. R.; Macedo, C. A.</p> <p>2016-01-01</p> <p>In this study, the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energies</span> of face-centered cubic Hubbard clusters are analyzed using the Lanczos method. Examination of the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span> as a function of the number of particle per site n showed an <span class="hlt">energy</span> minimum for face-centered cubic structures. This <span class="hlt">energy</span> minimum decreased in n with increasing coulombic interaction parameter U. We found that the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span> had a minimum at n = 0.6, when U = 3W, where W denotes the non-interacting <span class="hlt">energy</span> bandwidth and the face-centered cubic structure was ferromagnetic. These results, when compared with the properties of nickel, shows strong similarity with other finite temperature analyses in the literature and supports the Hirsh’s conjecture that the interatomic direct exchange interaction dominates in driving the system into a ferromagnetic phase. PMID:27583653</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013mss..confERJ12I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013mss..confERJ12I"><span>Deuteration Effect on the Nh/nd Stretch <span class="hlt">Band</span> of the Jet-Cooled 7-AZAINDOLE and its Tautomeric Dimers: Relation to the <span class="hlt">Ground-State</span> Double Proton-Transfer Reaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ishikawa, Haruki; Nakano, Takumi; Takashima, Tsukiko; Yabuguchi, Hiroki; Fuke, Kiyokazu</p> <p>2013-06-01</p> <p>In order to investigate the deuteration effect on the vibrational dynamics of the NH and/or ND stretch excited levels of the 7-azaindole (7-AI) normal dimer and its tautomeric dimer, we have carried out infrared spectroscopy of three isotopic species for each dimers; undeuterated one (NH-NH) and one or two hydrogen atom(s) of the NH groups is deuterated ones (NH-ND and ND-ND, respectively). It is found that the ND stretch <span class="hlt">band</span> profiles of the NH-ND and ND-ND tautomeric dimers are very similar with each other. This result is very distinct from the result of the comparison of the NH stretch <span class="hlt">band</span> profiles of the NH-NH and NH-ND dimers in our previous study. For a further discussion, we have examined the deuteration effect in the case of the 7-AI normal dimer. It is found that the NH stretch <span class="hlt">band</span> profiles of the NH-NH and the NH-ND dimers and also the ND stretch <span class="hlt">band</span> profiles of the NH-ND and the ND-ND dimers exhibit similar patterns, respectively. These facts indicates that the vibrational relaxation from the NH/ND stretch level of the normal dimer basically proceed within a monomer unit. The large deuteration effect of the NH stretch <span class="hlt">band</span> profile observed previously is found to be characteristic of the tautomeric dimer. This behavior is related to a large anharmonicity of the potential <span class="hlt">energy</span> surface originating from an existence of the double-proton transfer reaction barrier. H. Ishikawa, H. Yabuguchi, Y. Yamada, A. Fujihara, K. Fuke, J. Phys. Chem. A 114, 3199 (2010).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007NIMPB.254...69D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007NIMPB.254...69D"><span><span class="hlt">Ground</span> <span class="hlt">state</span> of a hydrogen ion molecule immersed in an inhomogeneous electron gas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diaz-Valdes, J.; Gutierrez, F. A.; Matamala, A. R.; Denton, C. D.; Vargas, P.; Valdes, J. E.</p> <p>2007-01-01</p> <p>In this work we have calculated the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span> of the hydrogen molecule, H2+, immersed in the highly inhomogeneous electron gas around a metallic surface within the local density approximation. The molecule is perturbed by the electron density of a crystalline surface of Au <1 0 0> with the internuclear axis parallel to the surface. The surface spatial electron density is calculated through a linearized <span class="hlt">band</span> structure method (LMTO-DFT). The <span class="hlt">ground</span> <span class="hlt">state</span> of the molecule-ion was calculated using the Born-Oppenheimer approximation for a fixed-ion while the screening effects of the inhomogeneous electron gas are depicted by a Thomas-Fermi like electrostatic potential. We found that within our model the molecular ion dissociates at the critical distance of 2.35 a.u. from the first atomic layer of the solid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22391531','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22391531"><span><span class="hlt">Ground-state</span> structures of Hafnium clusters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ng, Wei Chun; Yoon, Tiem Leong; Lim, Thong Leng</p> <p>2015-04-24</p> <p>Hafnium (Hf) is a very large tetra-valence d-block element which is able to form relatively long covalent bond. Researchers are interested to search for substitution to silicon in the semi-conductor industry. We attempt to obtain the <span class="hlt">ground-state</span> structures of small Hf clusters at both empirical and density-functional theory (DFT) levels. For calculations at the empirical level, charge-optimized many-body functional potential (COMB) is used. The lowest-<span class="hlt">energy</span> structures are obtained via a novel global-minimum search algorithm known as parallel tempering Monte-Carlo Basin-Hopping and Genetic Algorithm (PTMBHGA). The virtue of using COMB potential for Hf cluster calculation lies in the fact that by including the charge optimization at the valence shells, we can encourage the formation of proper bond hybridization, and thus getting the correct bond order. The obtained structures are further optimized using DFT to ensure a close proximity to the <span class="hlt">ground-state</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890007088','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890007088"><span><span class="hlt">Ground</span> <span class="hlt">state</span> of high-density matter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Copeland, ED; Kolb, Edward W.; Lee, Kimyeong</p> <p>1988-01-01</p> <p>It is shown that if an upper bound to the false vacuum <span class="hlt">energy</span> of the electroweak Higgs potential is satisfied, the true <span class="hlt">ground</span> <span class="hlt">state</span> of high-density matter is not nuclear matter, or even strange-quark matter, but rather a non-topological soliton where the electroweak symmetry is exact and the fermions are massless. This possibility is examined in the standard SU(3) sub C tensor product SU(2) sub L tensor product U(1) sub Y model. The bound to the false vacuum <span class="hlt">energy</span> is satisfied only for a narrow range of the Higgs boson masses in the minimal electroweak model (within about 10 eV of its minimum allowed value of 6.6 GeV) and a somewhat wider range for electroweak models with a non-minimal Higgs sector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770055574&hterms=Energy+star&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEnergy%2Bstar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770055574&hterms=Energy+star&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEnergy%2Bstar"><span>Variational calculation of <span class="hlt">ground-state</span> <span class="hlt">energy</span> of iron atoms and condensed matter in strong magnetic fields. [at neutron star surfaces</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Flowers, E. G.; Ruderman, M. A.; Lee, J.-F.; Sutherland, P. G.; Hillebrandt, W.; Mueller, E.</p> <p>1977-01-01</p> <p>Variational calculations of the binding <span class="hlt">energies</span> of iron atoms and condensed matter in strong magnetic fields (greater than 10 to the 12th gauss). These calculations include the electron exchange <span class="hlt">energy</span>. The cohesive <span class="hlt">energy</span> of the condensed matter, which is the difference between these two binding <span class="hlt">energies</span>, is of interest in pulsar theories and in the description of the surfaces of neutron stars. It is found that the cohesive <span class="hlt">energy</span> ranges from 2.6 keV to 8.0 keV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770055574&hterms=energy+fields&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Denergy%2Bfields','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770055574&hterms=energy+fields&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Denergy%2Bfields"><span>Variational calculation of <span class="hlt">ground-state</span> <span class="hlt">energy</span> of iron atoms and condensed matter in strong magnetic fields. [at neutron star surfaces</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Flowers, E. G.; Ruderman, M. A.; Lee, J.-F.; Sutherland, P. G.; Hillebrandt, W.; Mueller, E.</p> <p>1977-01-01</p> <p>Variational calculations of the binding <span class="hlt">energies</span> of iron atoms and condensed matter in strong magnetic fields (greater than 10 to the 12th gauss). These calculations include the electron exchange <span class="hlt">energy</span>. The cohesive <span class="hlt">energy</span> of the condensed matter, which is the difference between these two binding <span class="hlt">energies</span>, is of interest in pulsar theories and in the description of the surfaces of neutron stars. It is found that the cohesive <span class="hlt">energy</span> ranges from 2.6 keV to 8.0 keV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23574212','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23574212"><span>Valence excitation <span class="hlt">energies</span> of alkenes, carbonyl compounds, and azabenzenes by time-dependent density functional theory: linear response of the <span class="hlt">ground</span> <span class="hlt">state</span> compared to collinear and noncollinear spin-flip TDDFT with the Tamm-Dancoff approximation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Isegawa, Miho; Truhlar, Donald G</p> <p>2013-04-07</p> <p>Time-dependent density functional theory (TDDFT) holds great promise for studying photochemistry because of its affordable cost for large systems and for repeated calculations as required for direct dynamics. The chief obstacle is uncertain accuracy. There have been many validation studies, but there are also many formulations, and there have been few studies where several formulations were applied systematically to the same problems. Another issue, when TDDFT is applied with only a single exchange-correlation functional, is that errors in the functional may mask successes or failures of the formulation. Here, to try to sort out some of the issues, we apply eight formulations of adiabatic TDDFT to the first valence excitations of ten molecules with 18 density functionals of diverse types. The formulations examined are linear response from the <span class="hlt">ground</span> <span class="hlt">state</span> (LR-TDDFT), linear response from the <span class="hlt">ground</span> <span class="hlt">state</span> with the Tamm-Dancoff approximation (TDDFT-TDA), the original collinear spin-flip approximation with the Tamm-Dancoff (TD) approximation (SF1-TDDFT-TDA), the original noncollinear spin-flip approximation with the TDA approximation (SF1-NC-TDDFT-TDA), combined self-consistent-field (SCF) and collinear spin-flip calculations in the original spin-projected form (SF2-TDDFT-TDA) or non-spin-projected (NSF2-TDDFT-TDA), and combined SCF and noncollinear spin-flip calculations (SF2-NC-TDDFT-TDA and NSF2-NC-TDDFT-TDA). Comparing LR-TDDFT to TDDFT-TDA, we observed that the excitation <span class="hlt">energy</span> is raised by the TDA; this brings the excitation <span class="hlt">energies</span> underestimated by full linear response closer to experiment, but sometimes it makes the results worse. For ethylene and butadiene, the excitation <span class="hlt">energies</span> are underestimated by LR-TDDFT, and the error becomes smaller making the TDA. Neither SF1-TDDFT-TDA nor SF2-TDDFT-TDA provides a lower mean unsigned error than LR-TDDFT or TDDFT-TDA. The comparison between collinear and noncollinear kernels shows that the noncollinear kernel</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JChPh.138m4111I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JChPh.138m4111I"><span>Valence excitation <span class="hlt">energies</span> of alkenes, carbonyl compounds, and azabenzenes by time-dependent density functional theory: Linear response of the <span class="hlt">ground</span> <span class="hlt">state</span> compared to collinear and noncollinear spin-flip TDDFT with the Tamm-Dancoff approximation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Isegawa, Miho; Truhlar, Donald G.</p> <p>2013-04-01</p> <p>Time-dependent density functional theory (TDDFT) holds great promise for studying photochemistry because of its affordable cost for large systems and for repeated calculations as required for direct dynamics. The chief obstacle is uncertain accuracy. There have been many validation studies, but there are also many formulations, and there have been few studies where several formulations were applied systematically to the same problems. Another issue, when TDDFT is applied with only a single exchange-correlation functional, is that errors in the functional may mask successes or failures of the formulation. Here, to try to sort out some of the issues, we apply eight formulations of adiabatic TDDFT to the first valence excitations of ten molecules with 18 density functionals of diverse types. The formulations examined are linear response from the <span class="hlt">ground</span> <span class="hlt">state</span> (LR-TDDFT), linear response from the <span class="hlt">ground</span> <span class="hlt">state</span> with the Tamm-Dancoff approximation (TDDFT-TDA), the original collinear spin-flip approximation with the Tamm-Dancoff (TD) approximation (SF1-TDDFT-TDA), the original noncollinear spin-flip approximation with the TDA approximation (SF1-NC-TDDFT-TDA), combined self-consistent-field (SCF) and collinear spin-flip calculations in the original spin-projected form (SF2-TDDFT-TDA) or non-spin-projected (NSF2-TDDFT-TDA), and combined SCF and noncollinear spin-flip calculations (SF2-NC-TDDFT-TDA and NSF2-NC-TDDFT-TDA). Comparing LR-TDDFT to TDDFT-TDA, we observed that the excitation <span class="hlt">energy</span> is raised by the TDA; this brings the excitation <span class="hlt">energies</span> underestimated by full linear response closer to experiment, but sometimes it makes the results worse. For ethylene and butadiene, the excitation <span class="hlt">energies</span> are underestimated by LR-TDDFT, and the error becomes smaller making the TDA. Neither SF1-TDDFT-TDA nor SF2-TDDFT-TDA provides a lower mean unsigned error than LR-TDDFT or TDDFT-TDA. The comparison between collinear and noncollinear kernels shows that the noncollinear kernel</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5127192','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5127192"><span>Globally accurate potential <span class="hlt">energy</span> surface for the <span class="hlt">ground-state</span> HCS(X2A′) and its use in reaction dynamics</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Song, Yu-Zhi; Zhang, Lu-Lu; Gao, Shou-Bao; Meng, Qing-Tian</p> <p>2016-01-01</p> <p>A globally accurate many-body expansion potential <span class="hlt">energy</span> surface is reported for HCS(X2A′) by fitting a wealth of accurate ab initio <span class="hlt">energies</span> calculated at the multireference configuration interaction level using aug-cc-pVQZ and aug-cc-pV5Z basis sets via extrapolation to the complete basis set limit. The topographical features of the present potential <span class="hlt">energy</span> surface are examined in detail and is in good agreement with the raw ab initio results, as well as other theoretical results available in literatures. By utilizing the potential <span class="hlt">energy</span> surface of HCS(X2A′), the dynamic studies of the C(3P) + SH(X2Π) → H(2S) + CS(X1∑+) reaction has been carried out using quasi-classical trajectory method. PMID:27898106</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23666848','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23666848"><span>Accurate double many-body expansion potential <span class="hlt">energy</span> surface by extrapolation to the complete basis set limit and dynamics calculations for <span class="hlt">ground</span> <span class="hlt">state</span> of NH2.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Yongqing; Yuan, Jiuchuang; Chen, Maodu; Ma, Fengcai; Sun, Mengtao</p> <p>2013-07-15</p> <p>An accurate single-sheeted double many-body expansion potential <span class="hlt">energy</span> surface is reported for the title system. A switching function formalism has been used to warrant the correct behavior at the H2(X1Σg+)+N(2D) and NH (X3Σ-)+H(2S) dissociation channels involving nitrogen in the ground N(4S) and first excited N(2D) states. The topographical features of the novel global potential <span class="hlt">energy</span> surface are examined in detail, and found to be in good agreement with those calculated directly from the raw ab initio <span class="hlt">energies</span>, as well as previous calculations available in the literature. The novel surface can be using to treat well the Renner-Teller degeneracy of the 12A″ and 12A' states of NH 2. Such a work can both be recommended for dynamics studies of the N(2D)+H2 reaction and as building blocks for constructing the double many-body expansion potential <span class="hlt">energy</span> surface of larger nitrogen/hydrogen-containing systems. In turn, a test theoretical study of the reaction N(2D)+H2(X1Σg+)(ν=0,j=0)→NH (X3Σ-)+H(2S) has been carried out with the method of quantum wave packet on the new potential <span class="hlt">energy</span> surface. Reaction probabilities, integral cross sections, and differential cross sections have been calculated. Threshold exists because of the <span class="hlt">energy</span> barrier (68.5 meV) along the minimum <span class="hlt">energy</span> path. On the curve of reaction probability for total angular momentum J = 0, there are two sharp peaks just above threshold. The value of integral cross section increases quickly from zero to maximum with the increase of collision <span class="hlt">energy</span>, and then stays stable with small oscillations. The differential cross section result shows that the reaction is a typical forward and backward scatter in agreement with experimental measurement result. Copyright © 2013 Wiley Periodicals, Inc..</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AIPC.1447..843U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AIPC.1447..843U"><span>Electronic structure and <span class="hlt">ground</span> <span class="hlt">state</span> properties of A4[Cu4O4] (A=Li, Na, K and Rb): A first principle study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Umamaheswari, R.; Yogeswari, M.; Kalpana, G.</p> <p>2012-06-01</p> <p>The results of first principles calculations of the electronic <span class="hlt">band</span> structure and <span class="hlt">ground-state</span> properties of alkali metal copper oxides A4[Cu4O4] (A = Li, Na, K and Rb) compounds are in tetragonal body centered structure with two different space groups I-4m2 and I4/mmm. The calculations have been carried out using the tight-binding linear muffin-tin orbital method within the local density approximation. The total <span class="hlt">energies</span> calculated within the atomic sphere approximation where used to determine the <span class="hlt">ground-state</span> properties such as equilibrium lattice parameters, c/a ratio, the bulk modulus and cohesive <span class="hlt">energy</span> and these are found to be in good agreement with the available experimental values. The results of the electronic <span class="hlt">band</span> structure calculations show that LiCuO, KCuO and RbCuO are indirect <span class="hlt">band</span> gap semiconductors, whereas NaCuO is direct <span class="hlt">band</span> gap semiconductor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27301682','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27301682"><span>The inverse thermal spin-orbit torque and the relation of the Dzyaloshinskii-Moriya interaction to <span class="hlt">ground-state</span> <span class="hlt">energy</span> currents.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Freimuth, Frank; Blügel, Stefan; Mokrousov, Yuriy</p> <p>2016-08-10</p> <p>Using the Kubo linear-response formalism we derive expressions to calculate the electronic contribution to the heat current generated by magnetization dynamics in ferromagnetic metals with broken inversion symmetry and spin-orbit interaction (SOI). The effect of producing heat currents by magnetization dynamics constitutes the Onsager reciprocal of the thermal spin-orbit torque (TSOT), i.e. the generation of torques on the magnetization due to temperature gradients. We find that the <span class="hlt">energy</span> current driven by magnetization dynamics contains a contribution from the Dzyaloshinskii-Moriya interaction (DMI), which needs to be subtracted from the Kubo linear response of the <span class="hlt">energy</span> current in order to extract the heat current. We show that the expressions of the DMI coefficient can be derived elegantly from the DMI <span class="hlt">energy</span> current. Guided by formal analogies between the Berry phase theory of DMI on the one hand and the modern theory of orbital magnetization on the other hand we are led to an interpretation of the latter in terms of <span class="hlt">energy</span> currents as well. Based on ab initio calculations we investigate the electronic contribution to the heat current driven by magnetization dynamics in Mn/W(0 0 1) magnetic bilayers. We predict that fast domain walls drive strong heat currents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPCM...28E6001F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPCM...28E6001F"><span>The inverse thermal spin-orbit torque and the relation of the Dzyaloshinskii-Moriya interaction to <span class="hlt">ground-state</span> <span class="hlt">energy</span> currents</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Freimuth, Frank; Blügel, Stefan; Mokrousov, Yuriy</p> <p>2016-08-01</p> <p>Using the Kubo linear-response formalism we derive expressions to calculate the electronic contribution to the heat current generated by magnetization dynamics in ferromagnetic metals with broken inversion symmetry and spin-orbit interaction (SOI). The effect of producing heat currents by magnetization dynamics constitutes the Onsager reciprocal of the thermal spin-orbit torque (TSOT), i.e. the generation of torques on the magnetization due to temperature gradients. We find that the <span class="hlt">energy</span> current driven by magnetization dynamics contains a contribution from the Dzyaloshinskii-Moriya interaction (DMI), which needs to be subtracted from the Kubo linear response of the <span class="hlt">energy</span> current in order to extract the heat current. We show that the expressions of the DMI coefficient can be derived elegantly from the DMI <span class="hlt">energy</span> current. Guided by formal analogies between the Berry phase theory of DMI on the one hand and the modern theory of orbital magnetization on the other hand we are led to an interpretation of the latter in terms of <span class="hlt">energy</span> currents as well. Based on ab initio calculations we investigate the electronic contribution to the heat current driven by magnetization dynamics in Mn/W(0 0 1) magnetic bilayers. We predict that fast domain walls drive strong heat currents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JChPh.134i4306H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JChPh.134i4306H"><span>Accurate ab initio determination of the adiabatic potential <span class="hlt">energy</span> function and the Born-Oppenheimer breakdown corrections for the electronic <span class="hlt">ground</span> <span class="hlt">state</span> of LiH isotopologues</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holka, Filip; Szalay, Péter G.; Fremont, Julien; Rey, Michael; Peterson, Kirk A.; Tyuterev, Vladimir G.</p> <p>2011-03-01</p> <p>High level ab initio potential <span class="hlt">energy</span> functions have been constructed for LiH in order to predict vibrational levels up to dissociation. After careful tests of the parameters of the calculation, the final adiabatic potential <span class="hlt">energy</span> function has been composed from: (a) an ab initio nonrelativistic potential obtained at the multireference configuration interaction with singles and doubles level including a size-extensivity correction and quintuple-sextuple ζ extrapolations of the basis, (b) a mass-velocity-Darwin relativistic correction, and (c) a diagonal Born-Oppenheimer (BO) correction. Finally, nonadiabatic effects have also been considered by including a nonadiabatic correction to the kinetic <span class="hlt">energy</span> operator of the nuclei. This correction is calculated from nonadiabatic matrix elements between the ground and excited electronic states. The calculated vibrational levels have been compared with those obtained from the experimental data [J. A. Coxon and C. S. Dickinson, J. Chem. Phys. 134, 9378 (2004)]. It was found that the calculated BO potential results in vibrational levels which have root mean square (rms) deviations of about 6-7 cm-1 for LiH and ˜3 cm-1 for LiD. With all the above mentioned corrections accounted for, the rms deviation falls down to ˜1 cm-1. These results represent a drastic improvement over previous theoretical predictions of vibrational levels for all isotopologues of LiH.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21384968','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21384968"><span>Accurate ab initio determination of the adiabatic potential <span class="hlt">energy</span> function and the Born-Oppenheimer breakdown corrections for the electronic <span class="hlt">ground</span> <span class="hlt">state</span> of LiH isotopologues.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Holka, Filip; Szalay, Péter G; Fremont, Julien; Rey, Michael; Peterson, Kirk A; Tyuterev, Vladimir G</p> <p>2011-03-07</p> <p>High level ab initio potential <span class="hlt">energy</span> functions have been constructed for LiH in order to predict vibrational levels up to dissociation. After careful tests of the parameters of the calculation, the final adiabatic potential <span class="hlt">energy</span> function has been composed from: (a) an ab initio nonrelativistic potential obtained at the multireference configuration interaction with singles and doubles level including a size-extensivity correction and quintuple-sextuple ζ extrapolations of the basis, (b) a mass-velocity-Darwin relativistic correction, and (c) a diagonal Born-Oppenheimer (BO) correction. Finally, nonadiabatic effects have also been considered by including a nonadiabatic correction to the kinetic <span class="hlt">energy</span> operator of the nuclei. This correction is calculated from nonadiabatic matrix elements between the ground and excited electronic states. The calculated vibrational levels have been compared with those obtained from the experimental data [J. A. Coxon and C. S. Dickinson, J. Chem. Phys. 134, 9378 (2004)]. It was found that the calculated BO potential results in vibrational levels which have root mean square (rms) deviations of about 6-7 cm(-1) for LiH and ∼3 cm(-1) for LiD. With all the above mentioned corrections accounted for, the rms deviation falls down to ∼1 cm(-1). These results represent a drastic improvement over previous theoretical predictions of vibrational levels for all isotopologues of LiH.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014isms.confERC06U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014isms.confERC06U"><span>Rotational Spectrum of SO_3 and Theoretical Evidence for the Formation of Rotational <span class="hlt">Energy</span> Level Clusters in its Vibrational <span class="hlt">Ground</span> <span class="hlt">State</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Underwood, Daniel S.; Yurchenko, Sergei N.; Tennyson, Jonathan; Jensen, Per</p> <p>2014-06-01</p> <p>The structure of the purely rotational spectrum of sulphur trioxide SO_3 is investigated using a new synthetic line list. The list combines line positions from an empirical model with line intensities determined, in the form of Einstein coefficients, from variationally computed ro-vibrational wavefunctions in conjunction with an ab initio dipole moment surface. The empirical model providing the line positions involves an effective, Watsonian-type rotational Hamiltonian with literature parameter values resulting from least-squares fittings to observed transition frequencies. The formation of so-called rotational <span class="hlt">energy</span> clusters at high rotational excitation are investigated. The SO_3 molecule is planar at equilibrium and exhibits a unique type of rotational-<span class="hlt">energy</span> clustering associated with unusual stabilization axes perpendicular to the S--O bonds. This behaviour is characterized theoretically in the J range from 100 through 250. The wavefunctions for these cluster states are analysed, and the results are compared to those of a classical analysis in terms of the rotational-<span class="hlt">energy</span>-surface formalism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JChPh.139t4305D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JChPh.139t4305D"><span>A global ab initio potential <span class="hlt">energy</span> surface for the X 2A' <span class="hlt">ground</span> <span class="hlt">state</span> of the Si + OH → SiO + H reaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dayou, Fabrice; Duflot, Denis; Rivero-Santamaría, Alejandro; Monnerville, Maurice</p> <p>2013-11-01</p> <p>We report the first global potential <span class="hlt">energy</span> surface (PES) for the X 2A' ground electronic state of the Si(3P) + OH(X2Π) → SiO(X^1Σ _g^+) + H(2S) reaction. The PES is based on a large number of ab initio <span class="hlt">energies</span> obtained from multireference configuration interaction calculations plus Davidson correction (MRCI+Q) using basis sets of quadruple zeta quality. Corrections were applied to the ab initio <span class="hlt">energies</span> in the reactant channel allowing a proper description of long-range interactions between Si(3P) and OH(X2Π). An analytical representation of the global PES has been developed by means of the reproducing kernel Hilbert space method. The reaction is found barrierless. Two minima, corresponding to the SiOH and HSiO isomers, and six saddle points, among which the isomerization transition state, have been characterized on the PES. The vibrational spectra of the SiOH/HSiO radicals have been computed from second-order perturbation theory and quantum dynamics methods. The structural, energetic, and spectroscopic properties of the two isomers are in good agreement with experimental data and previous high quality calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/627934','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/627934"><span>Neutrino <span class="hlt">ground</span> <span class="hlt">state</span> in a dense star</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kiers, K.; Tytgat, M.H. |</p> <p>1998-05-01</p> <p>It has recently been argued that long range forces due to the exchange of massless neutrinos give rise to a very large self-<span class="hlt">energy</span> in a dense, finite-ranged, weakly charged medium. Such an effect, if real, would destabilize a neutron star. To address this issue we have studied the related problem of a massless neutrino field in the presence of an external, static electroweak potential of finite range. To be precise, we have computed to one loop the exact vacuum <span class="hlt">energy</span> for the case of a spherical square well potential of depth {alpha} and radius R. For small wells, the vacuum <span class="hlt">energy</span> is reliably determined by a perturbative expansion in the external potential. For large wells, however, the perturbative expansion breaks down. A manifestation of this breakdown is that the vacuum carries a non-zero neutrino charge. The <span class="hlt">energy</span> and neutrino charge of the <span class="hlt">ground</span> <span class="hlt">state</span> are, to a good approximation for large wells, those of a neutrino condensate with chemical potential {mu}={alpha}. Our results demonstrate explicitly that long-range forces due to the exchange of massless neutrinos do not threaten the stability of neutron stars. {copyright} {ital 1998} {ital The American Physical Society}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21855825','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21855825"><span>The <span class="hlt">ground</span> <span class="hlt">states</span> of iron(III) porphines: role of entropy-enthalpy compensation, Fermi correlation, dispersion, and zero-point <span class="hlt">energies</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kepp, Kasper P</p> <p>2011-10-01</p> <p>Porphyrins are much studied due to their biochemical relevance and many applications. The density functional TPSSh has previously accurately described the <span class="hlt">energy</span> of close-lying electronic states of transition metal systems such as porphyrins. However, a recent study questioned this conclusion based on calculations of five iron(III) porphines. Here, we compute the geometries of 80 different electronic configurations and the free <span class="hlt">energies</span> of the most stable configurations with the functionals TPSSh, TPSS, and B3LYP. Zero-point <span class="hlt">energies</span> and entropy favor high-spin by ~4kJ/mol and 0-10kJ/mol, respectively. When these effects are included, and all electronic configurations are evaluated, TPSSh correctly predicts the spin of all the four difficult phenylporphine cases and is within the lower bound of uncertainty of any known theoretical method for the fifth, iron(III) chloroporphine. Dispersion computed with DFT-D3 favors low-spin by 3-53kJ/mol (TPSSh) or 4-15kJ/mol (B3LYP) due to the attractive r(-6) term and the shorter distances in low-spin. The very large and diverse corrections from TPSS and TPSSh seem less consistent with the similarity of the systems than when calculated from B3LYP. If the functional-specific corrections are used, B3LYP and TPSSh are of equal accuracy, and TPSS is much worse, whereas if the physically reasonable B3LYP-computed dispersion effect is used for all functionals, TPSSh is accurate for all systems. B3LYP is significantly more accurate when dispersion is added, confirming previous results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96d1112M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96d1112M"><span>Antibonding <span class="hlt">ground</span> <span class="hlt">state</span> of adatom molecules in bulk Dirac semimetals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marques, Y.; Obispo, A. E.; Ricco, L. S.; de Souza, M.; Shelykh, I. A.; Seridonio, A. C.</p> <p>2017-07-01</p> <p>The <span class="hlt">ground</span> <span class="hlt">state</span> of the diatomic molecules in nature is inevitably bonding, and its first excited state is antibonding. We demonstrate theoretically that, for a pair of distant adatoms placed buried in three-dimensional-Dirac semimetals, this natural order of the states can be reversed and an antibonding <span class="hlt">ground</span> <span class="hlt">state</span> occurs at the lowest <span class="hlt">energy</span> of the so-called bound states in the continuum. We propose an experimental protocol with the use of a scanning tunneling microscope tip to visualize the topographic map of the local density of states on the surface of the system to reveal the emerging physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22028023','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22028023"><span><span class="hlt">Ground</span> <span class="hlt">state</span> microstructure of a ferrofluid thin layer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Prokopieva, T. A.; Danilov, V. A.; Kantorovich, S. S.</p> <p>2011-09-15</p> <p>Using a fine weave of theoretical analysis and computer simulations, we found various aggregates of magnetic single-domain nanoparticles, which can form in a quasi-two-dimensional (q2D) ferrofluid layer at low temperatures. Our theoretical investigation allowed us to obtain exact expressions and their asymptotes for the <span class="hlt">energies</span> of each configuration. Thus, for ferrofluid q2D layers it proved possible to identify the <span class="hlt">ground</span> <span class="hlt">states</span> as a function of the particle number, size, and other system parameters. Our suggested approach can be used for the investigation of <span class="hlt">ground</span> <span class="hlt">state</span> structures in systems with more complex interparticle interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20957893','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20957893"><span>Variational Wave Functions and Their Overlap with the <span class="hlt">Ground</span> <span class="hlt">State</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mora, Christophe; Waintal, Xavier</p> <p>2007-07-20</p> <p>An intrinsic measure of the quality of a variational wave function is given by its overlap with the <span class="hlt">ground</span> <span class="hlt">state</span> of the system. We derive a general formula to compute this overlap when quantum dynamics in imaginary time is accessible. The overlap is simply related to the area under the E({tau}) curve, i.e., the <span class="hlt">energy</span> as a function of imaginary time. This has important applications to, for example, quantum Monte Carlo simulations where the overlap becomes as a simple by-product of routine simulations. As a result, we find that the practical definition of a good variational wave function for quantum Monte Carlo simulations, i.e., fast convergence to the <span class="hlt">ground</span> <span class="hlt">state</span>, is equivalent to a good overlap with the actual <span class="hlt">ground</span> <span class="hlt">state</span> of the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984PhRvB..29.3101L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984PhRvB..29.3101L"><span><span class="hlt">Ground-state</span> charge transfer as a mechanism for surface-enhanced Raman scattering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lippitsch, Max E.</p> <p>1984-03-01</p> <p>A model is presented for the contribution of <span class="hlt">ground-state</span> charge transfer between a metal and adsorbate to surface-enhanced Raman scattering (SERS). It is shown that this contribution can be understood using the vibronic theory for calculating Raman intensities. The enhancement is due to vibronic coupling of the molecular <span class="hlt">ground</span> <span class="hlt">state</span> to the metal states, the coupling mechanism being a modulation of the <span class="hlt">ground-state</span> charge-transfer <span class="hlt">energy</span> by the molecular vibrations. An analysis of the coupling operator gives the selection rules for this process, which turn out to be dependent on the overall symmetry of the adsorbate-metal system, even if the charge transfer is small enough for the symmetry of the adsorbate to remain the same as that of the free molecule. It is shown that the model can yield predictions on the properties of SERS, e.g., specificity to adsorption geometry, appearance of forbidden <span class="hlt">bands</span>, dependence on the applied potential, and dependence on the excitation wavelength. The predictions are in good agreement with experimental results. It is also deduced from this model that in many cases atomic-scale roughness is a prerequisite for the observation of SERS. A result on the magnitude of the enhancement can only be given in a crude approximation. Although in most cases an additional electromagnetic enhancement seems to be necessary to give an observable signal, this charge-transfer mechanism should be important in many SERS systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22979857','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22979857"><span>Radical ions with nearly degenerate <span class="hlt">ground</span> <span class="hlt">state</span>: correlation between the rate of spin-lattice relaxation and the structure of adiabatic potential <span class="hlt">energy</span> surface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Borovkov, V I; Beregovaya, I V; Shchegoleva, L N; Potashov, P A; Bagryansky, V A; Molin, Y N</p> <p>2012-09-14</p> <p>Paramagnetic spin-lattice relaxation (SLR) in radical cations (RCs) of the cycloalkane series in liquid solution was studied and analyzed from the point of view of the correlation between the relaxation rate and the structure of the adiabatic potential <span class="hlt">energy</span> surface (PES) of the RCs. SLR rates in the RCs formed in x-ray irradiated n-hexane solutions of the cycloalkanes studied were measured with the method of time-resolved magnetic field effect in the recombination fluorescence of spin-correlated radical ion pairs. Temperature and, for some cycloalkanes, magnetic field dependences of the relaxation rate were determined. It was found that the conventional Redfield theory of the paramagnetic relaxation as applied to the results on cyclohexane RC, gave a value of about 0.2 ps for the correlation time of the perturbation together with an unrealistically high value of 0.1 T in field units for the matrix element of the relaxation transition. The PES structure was obtained with the DFT quantum-chemical calculations. It was found that for all of the cycloalkanes RCs considered, including low symmetric alkyl-substituted ones, the adiabatic PESes were surfaces of pseudorotation due to avoided crossing. In the RCs studied, a correlation between the SLR rate and the calculated barrier height to the pseudorotation was revealed. For RCs with a higher relaxation rate, the apparent activation <span class="hlt">energies</span> for the SLR were similar to the calculated heights of the barrier. To rationalize the data obtained it was assumed that the vibronic states degeneracy, which is specific for Jahn-Teller active cyclohexane RC, was approximately kept in the RCs of substituted cycloalkanes for the vibronic states with the <span class="hlt">energies</span> above and close to the barrier height to the pseudorotation. It was proposed that the effective spin-lattice relaxation in a radical with nearly degenerate low-lying vibronic states originated from stochastic crossings of the vibronic levels that occur due to fluctuations of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986JPhB...19L.639F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986JPhB...19L.639F"><span>The wave function for the <span class="hlt">ground</span> <span class="hlt">state</span> of H</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fontenelle, Marcia T.; Gallas, Jason A. C.; Gallas, Marcia R.</p> <p>1986-10-01</p> <p>The <span class="hlt">ground-state</span> <span class="hlt">energy</span> of H(-) is investigated using a variational function proposed by Wu and Tsai (1985). Contrary to the conclusions of Wu and Tsai, it is found that the Wu and Tsai function produces results comparable with a previous calculation of Williamson (1942). Furthermore, the explicit formulas given in the present paper can easily be applied to the helium isoelectronic series.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28228038','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28228038"><span>On the piecewise convex or concave nature of <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span> as a function of fractional number of electrons for approximate density functionals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Chen; Yang, Weitao</p> <p>2017-02-21</p> <p>We provide a rigorous proof that the Hartree Fock <span class="hlt">energy</span>, as a function of the fractional electron number, E(N), is piecewise concave. Moreover, for semi-local density functionals, we show that the piecewise convexity of the E(N) curve, as stated in the literature, is not generally true for all fractions. By an analysis based on exchange-only local density approximation and careful examination of the E(N) curve, we find for some systems, there exists a very small concave region, corresponding to adding a small fraction of electrons to the integer system, while the remaining E(N) curve is convex. Several numerical examples are provided as verification. Although the E(N) curve is not convex everywhere in these systems, the previous conclusions on the consequence of the delocalization error in the commonly used density functional approximations, in particular, the underestimation of ionization potential, and the overestimation of electron affinity, and other related issues, remain unchanged. This suggests that instead of using the term convexity, a modified and more rigorous description for the delocalization error is that the E(N) curve lies below the straight line segment across the neighboring integer points for these approximate functionals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/961269','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/961269"><span>Implementation of a fast analytic <span class="hlt">ground</span> <span class="hlt">state</span> potential <span class="hlt">energy</span> surface for the N({sup 2}D)+H{sub 2} reaction.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ho, T.-S.; Rabitz, H.; Aoiz, F. J.; Banares, L.; Vazquez, S. A.; Harding, L. B.; Chemistry; Princeton Univ.; Univ. Complutense</p> <p>2003-08-08</p> <p>A new implementation is presented for the potential <span class="hlt">energy</span> surface (PES) of the 1{sup 2}A' state of the N({sup 2}D)+H{sub 2} system based on a set of 2715 ab initio points resulting from the multireference configuration interaction (MRCI) calculations. The implementation is carried out using the reproducing Kernel Hilbert Space interpolation method. Range parameters, via bond-order-like coordinates, are properly chosen to render a sufficiently short-range three-body interaction and a regularization procedure is invoked to yield a globally smooth PES. A fast algorithm, with the help of low-order spline reproducing kernels, is implemented for the computation of the PES and, particularly, its gradients, whose fast evaluation is essential for large scale quasi-classical trajectory calculations. It is found that the new PES can be evaluated more than ten times faster than that of an existing (old) PES based on a smaller number (1141) of data points resulting from the same MRCI calculations and a similar interpolation procedure. Although there is a general good correspondence between the two surfaces, the new PES is in much better agreement with the ab initio calculations, especially in key stationary point regions including the C{sub 2v} minimum, the C{sub 2v} transition state, and the N-H-H linear barrier. Moreover, the new PES is free of spurious small scale features. Analytic gradients are made available in the new PES code to further facilitate quasiclassical trajectory calculations, which have been performed and compared with the results based on the old surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PSST...24b5036C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PSST...24b5036C"><span>Experimental evidence of resonant <span class="hlt">energy</span> collisional transfers between argon 1s and 2p states and <span class="hlt">ground</span> <span class="hlt">state</span> H atoms by laser collisional induced fluorescence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carbone, Emile; van Dijk, Jan; Kroesen, Gerrit</p> <p>2015-04-01</p> <p>In this paper, laser collisional induced fluorescence (LCIF) is used to probe resonant excitation transfers in an argon/hydrogen plasma resulting from heavy particle collisions. Different radiative transitions between the 1s and 2p states (in Paschen's notation) of argon are optically pumped by a nanosecond laser pulse. The spontaneous fluorescence and collisional responses of the argon and hydrogen systems are monitored by optical emission spectroscopy. A surfatron plasma source is used to generate an argon plasma with a few per cent hydrogen addition at pressures between 0.65 and 20 mbar. The electron density is measured independently by means of Thomson scattering. The overall response of the plasma due to optical pumping of argon is briefly discussed and an overview of the known heteronuclear excitation transfers in an argon/hydrogen plasma is given. The propagation of the shortcut in the Ar(1s) to H(n = 2) excitation transfer due to the optical pumping of the Ar(1s) states is seen in the atomic hydrogen LCIF responses. For the first time, we give direct experimental evidence of the existence of an efficient excitation transfer: Additionally, measurements are performed in order to estimate the resonant <span class="hlt">energy</span> transfer between the resonant argon 1s states and hydrogen atoms: for which no previously measured cross sections could be found in the literature. These are extra quenching channels of argon 1s and 2p states that should be included in collisional-radiative modeling of argon-hydrogen discharges. The high repetition rate of the dye laser allows us to obtain a high sensitivity in the measurements. LCIF is shown to be a powerful tool for unraveling electron and also heavy particle excitation channels in situ in the plasma phase. The technique was previously developed for measuring electron or species densities locally in the plasma, but we show that it can be advantageously used to probe collisional transfers between very short-lived species which exist</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25974459','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25974459"><span><span class="hlt">Ground</span> <span class="hlt">states</span> for nonuniform periodic Ising chains.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Martínez-Garcilazo, J P; Ramírez, C</p> <p>2015-04-01</p> <p>We generalize Morita's works [J. Phys. A 7, 289 (1974); J. Phys. A 7, 1613 (1974)] on <span class="hlt">ground</span> <span class="hlt">states</span> of Ising chains, for chains with a periodic structure and different spins, to any interaction order. The main assumption is translational invariance. The length of the irreducible blocks is a multiple of the period of the chain. If there is parity invariance, it restricts the length in general only in the diatomic case. There are degenerated states and under certain circumstances there could be nonregular <span class="hlt">ground</span> <span class="hlt">states</span>. We illustrate the results and give the <span class="hlt">ground</span> <span class="hlt">state</span> diagrams in several cases.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23445075','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23445075"><span>Negative ion photoelectron spectroscopy confirms the prediction that (CO)5 and (CO)6 each has a singlet <span class="hlt">ground</span> <span class="hlt">state</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bao, Xiaoguang; Hrovat, David A; Borden, Weston Thatcher; Wang, Xue-Bin</p> <p>2013-03-20</p> <p>Cyclobutane-1,2,3,4-tetraone has been both predicted and found to have a triplet <span class="hlt">ground</span> <span class="hlt">state</span>, in which a b2g σ molecular orbital (MO) and an a2u π MO are each singly occupied. In contrast, (CO)5 and (CO)6 have each been predicted to have a singlet <span class="hlt">ground</span> <span class="hlt">state</span>. These predictions have been tested by generating the (CO)5(•-) and (CO)6(•-) radical anions in the gas phase, using electrospray vaporization of solutions of, respectively, the croconate (CO)5(2-) and rhodizonate (CO)6(2-) dianions. The negative ion photoelectron (NIPE) spectrum of the (CO)5(•-) radical anion gives an electron affinity of EA = 3.830 eV for formation of the singlet <span class="hlt">ground</span> <span class="hlt">state</span> of (CO)5. The triplet is found to be higher in <span class="hlt">energy</span> by 0.850 eV (19.6 kcal/mol). The NIPE spectrum of the (CO)6(•-) radical anion gives EA = 3.785 eV for forming the singlet <span class="hlt">ground</span> <span class="hlt">state</span> of (CO)6, with the triplet state higher in <span class="hlt">energy</span> by 0.915 eV (21.1 kcal/mol). (RO)CCSD(T)/aug-cc-pVTZ//(U)B3LYP/6-311+G(2df) calculations give EA values that are only approximately 1 kcal/mol lower than those measured and ΔE(ST) values that are 2-3 kcal/mol higher than those obtained from the NIPE spectra. Calculations of the Franck-Condon factors for transitions from the <span class="hlt">ground</span> <span class="hlt">state</span> of each radical anion, (CO)n(•-) to the lowest singlet and triplet states of the n = 4-6 neutrals, nicely reproduce all of the observed vibrational features in the low-binding <span class="hlt">energy</span> regions of all three NIPE spectra. Thus, the calculations of both the <span class="hlt">energies</span> and vibrational structures of the two lowest <span class="hlt">energy</span> <span class="hlt">bands</span> in each of the NIPE spectra support the interpretation of the spectra in terms of a singlet <span class="hlt">ground</span> <span class="hlt">state</span> for (CO)5 and (CO)6 but a triplet <span class="hlt">ground</span> <span class="hlt">state</span> for (CO)4.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1007619','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1007619"><span>Triplet (S = 1) <span class="hlt">Ground</span> <span class="hlt">State</span> Aminyl Diradical</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rajca, Andrzej; Shiraishi, Kouichi; Pink, Maren; Rajca, Suchada</p> <p>2008-04-02</p> <p>Aminyl diradical, which is stable in solution at low temperatures, is prepared. EPR spectra and SQUID magnetometry indicate that the diradical is planar and it possesses triplet <span class="hlt">ground</span> <span class="hlt">state</span>, with strong ferromagnetic coupling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20783299','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20783299"><span>Multireference configuration interaction calculations for the F({sup 2}P)+HCl{yields}HF+Cl({sup 2}P) reaction: A correlation scaled <span class="hlt">ground</span> <span class="hlt">state</span> (1 {sup 2}A{sup '}) potential <span class="hlt">energy</span> surface</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Deskevich, Michael P.; Hayes, Michael Y.; Takahashi, Kaito; Skodje, Rex T.; Nesbitt, David J.</p> <p>2006-06-14</p> <p>This paper presents a new <span class="hlt">ground</span> <span class="hlt">state</span> (1 {sup 2}A{sup '}) electronic potential <span class="hlt">energy</span> surface for the F({sup 2}P)+HCl{yields}HF+Cl({sup 2}P) reaction. The ab initio calculations are done at the multireference configuration interaction+Davidson correction (MRCI+Q) level of theory by complete basis set extrapolation of the aug-cc-pVnZ (n=2,3,4) <span class="hlt">energies</span>. Due to low-lying charge transfer states in the transition state region, the molecular orbitals are obtained by six-state dynamically weighted multichannel self-consistent field methods. Additional perturbative refinement of the <span class="hlt">energies</span> is achieved by implementing simple one-parameter correlation <span class="hlt">energy</span> scaling to reproduce the experimental exothermicity ({delta}E=-33.06 kcal/mol) for the reaction. Ab initio points are fitted to an analytical function based on sum of two- and three-body contributions, yielding a rms deviation of <0.3 kcal/mol for all geometries below 10 kcal/mol above the barrier. Of particular relevance to nonadiabatic dynamics, the calculations show significant multireference character in the transition state region, which is located 3.8 kcal/mol with respect to F+HCl reactants and features a strongly bent F-H-Cl transition state geometry ({theta}{approx_equal}123.5 deg. ). Finally, the surface also exhibits two conical intersection seams that are energetically accessible at low collision <span class="hlt">energies</span>. These seams arise naturally from allowed crossings in the C{sub {infinity}}{sub v} linear configuration that become avoided in C{sub s} bent configurations of both the reactant and product, and should be a hallmark of all X-H-Y atom transfer reaction dynamics between ({sup 2}P) halogen atoms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvX...5b1020T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvX...5b1020T"><span>Ensemble Theory for Stealthy Hyperuniform Disordered <span class="hlt">Ground</span> <span class="hlt">States</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Torquato, S.; Zhang, G.; Stillinger, F. H.</p> <p>2015-04-01</p> <p>It has been shown numerically that systems of particles interacting with isotropic "stealthy" bounded long-ranged pair potentials (similar to Friedel oscillations) have classical <span class="hlt">ground</span> <span class="hlt">states</span> that are (counterintuitively) disordered, hyperuniform, and highly degenerate. Disordered hyperuniform systems have received attention recently because they are distinguishable exotic states of matter poised between a crystal and liquid that are endowed with novel thermodynamic and physical properties. The task of formulating an ensemble theory that yields analytical predictions for the structural characteristics and other properties of stealthy degenerate <span class="hlt">ground</span> <span class="hlt">states</span> in d -dimensional Euclidean space Rd is highly nontrivial because the dimensionality of the configuration space depends on the number density ρ and there is a multitude of ways of sampling the <span class="hlt">ground-state</span> manifold, each with its own probability measure for finding a particular <span class="hlt">ground-state</span> configuration. The purpose of this paper is to take some initial steps in this direction. Specifically, we derive general exact relations for thermodynamic properties (<span class="hlt">energy</span>, pressure, and isothermal compressibility) that apply to any <span class="hlt">ground-state</span> ensemble as a function of ρ in any d , and we show how disordered degenerate <span class="hlt">ground</span> <span class="hlt">states</span> arise as part of the <span class="hlt">ground-state</span> manifold. We also derive exact integral conditions that both the pair correlation function g2(r ) and structure factor S (k ) must obey for any d . We then specialize our results to the canonical ensemble (in the zero-temperature limit) by exploiting an ansatz that stealthy states behave remarkably like "pseudo"-equilibrium hard-sphere systems in Fourier space. Our theoretical predictions for g2(r ) and S (k ) are in excellent agreement with computer simulations across the first three space dimensions. These results are used to obtain order metrics, local number variance, and nearest-neighbor functions across dimensions. We also derive accurate analytical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/914540','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/914540"><span>Lattice QCD Beyond <span class="hlt">Ground</span> <span class="hlt">States</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Huey-Wen Lin; Saul D. Cohen</p> <p>2007-09-11</p> <p>In this work, we apply black box methods (methods not requiring input) to find excited-state <span class="hlt">energies</span>. A variety of such methods for lattice QCD were introduced at the 3rd iteration of the numerical workshop series. We first review a selection of approaches that have been used in lattice calculations to determine multiple <span class="hlt">energy</span> states: multiple correlator fits, the variational method and Bayesian fitting. In the second half, we will focus on a black box method, the multi-effective mass. We demonstrate the approach on a toy model, as well as on real lattice data, extracting multiple states from single correlators. Without complicated operator construction or specialized fitting programs, the black box method shows good consistency with the traditional approaches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4960298','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4960298"><span>Magnetic <span class="hlt">ground</span> <span class="hlt">state</span> of FeSe</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Qisi; Shen, Yao; Pan, Bingying; Zhang, Xiaowen; Ikeuchi, K.; Iida, K.; Christianson, A. D.; Walker, H. C.; Adroja, D. T.; Abdel-Hafiez, M.; Chen, Xiaojia; Chareev, D. A.; Vasiliev, A. N.; Zhao, Jun</p> <p>2016-01-01</p> <p>Elucidating the nature of the magnetism of a high-temperature superconductor is crucial for establishing its pairing mechanism. The parent compounds of the cuprate and iron-pnictide superconductors exhibit Néel and stripe magnetic order, respectively. However, FeSe, the structurally simplest iron-based superconductor, shows nematic order (Ts=90 K), but not magnetic order in the parent phase, and its magnetic <span class="hlt">ground</span> <span class="hlt">state</span> is intensely debated. Here we report inelastic neutron-scattering experiments that reveal both stripe and Néel spin fluctuations over a wide <span class="hlt">energy</span> range at 110 K. On entering the nematic phase, a substantial amount of spectral weight is transferred from the Néel to the stripe spin fluctuations. Moreover, the total fluctuating magnetic moment of FeSe is ∼60% larger than that in the iron pnictide BaFe2As2. Our results suggest that FeSe is a novel S=1 nematic quantum-disordered paramagnet interpolating between the Néel and stripe magnetic instabilities. PMID:27431986</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27431986','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27431986"><span>Magnetic <span class="hlt">ground</span> <span class="hlt">state</span> of FeSe.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Qisi; Shen, Yao; Pan, Bingying; Zhang, Xiaowen; Ikeuchi, K; Iida, K; Christianson, A D; Walker, H C; Adroja, D T; Abdel-Hafiez, M; Chen, Xiaojia; Chareev, D A; Vasiliev, A N; Zhao, Jun</p> <p>2016-07-19</p> <p>Elucidating the nature of the magnetism of a high-temperature superconductor is crucial for establishing its pairing mechanism. The parent compounds of the cuprate and iron-pnictide superconductors exhibit Néel and stripe magnetic order, respectively. However, FeSe, the structurally simplest iron-based superconductor, shows nematic order (Ts=90 K), but not magnetic order in the parent phase, and its magnetic <span class="hlt">ground</span> <span class="hlt">state</span> is intensely debated. Here we report inelastic neutron-scattering experiments that reveal both stripe and Néel spin fluctuations over a wide <span class="hlt">energy</span> range at 110 K. On entering the nematic phase, a substantial amount of spectral weight is transferred from the Néel to the stripe spin fluctuations. Moreover, the total fluctuating magnetic moment of FeSe is ∼60% larger than that in the iron pnictide BaFe2As2. Our results suggest that FeSe is a novel S=1 nematic quantum-disordered paramagnet interpolating between the Néel and stripe magnetic instabilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhLB..717..242S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhLB..717..242S"><span>Strangeness in the baryon <span class="hlt">ground</span> <span class="hlt">states</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Semke, A.; Lutz, M. F. M.</p> <p>2012-10-01</p> <p>We compute the strangeness content of the baryon octet and decuplet states based on an analysis of recent lattice simulations of the BMW, PACS, LHPC and HSC groups for the pion-mass dependence of the baryon masses. Our results rely on the relativistic chiral Lagrangian and large-Nc sum rule estimates of the counter terms relevant for the baryon masses at N3LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self <span class="hlt">energies</span>. A simultaneous description of the lattice results of the BMW, LHPC, PACS and HSC groups is achieved. From a global fit we determine the axial coupling constants F ≃ 0.45 and D ≃ 0.80 in agreement with their values extracted from semi-leptonic decays of the baryons. Moreover, various flavor symmetric limits of baron octet and decuplet masses as obtained by the QCDSF-UKQCD group are recovered. We predict the pion- and strangeness sigma terms and the pion-mass dependence of the octet and decuplet <span class="hlt">ground</span> <span class="hlt">states</span> at different strange quark masses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AdWR...30.2262L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AdWR...30.2262L"><span>Analytical solutions for bacterial <span class="hlt">energy</span> taxis (chemotaxis): Traveling bacterial <span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Long, Wei; Hilpert, Markus</p> <p>2007-11-01</p> <p>Motile bacteria may form <span class="hlt">bands</span> that travel with a constant speed of propagation through a medium containing a dissolved substrate, to which they respond <span class="hlt">energy</span> tactically. We generalize the analytical solution by Keller and Segel for such <span class="hlt">bands</span> by accounting for (1) the presence of a porous medium, (2) substrate consumption described by a Monod kinetics model, and (3) an <span class="hlt">energy</span> tactic response model derived by Rivero et al. Specifically, we determine the concentration profiles of the bacteria and the substrate. We also derive various expressions for the <span class="hlt">band</span> velocity. The <span class="hlt">band</span> velocity is also shown to equal the <span class="hlt">energy</span> tactic velocity at the bacterial peak divided by tortuosity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1248866-nuclear-ground-state-masses-deformations-frdm','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1248866-nuclear-ground-state-masses-deformations-frdm"><span>Nuclear <span class="hlt">ground-state</span> masses and deformations: FRDM(2012)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Moller, P.; Sierk, A. J.; Ichikawa, T.; ...</p> <p>2016-03-25</p> <p>Here, we tabulate the atomic mass excesses and binding <span class="hlt">energies</span>, <span class="hlt">ground-state</span> shell-plus-pairing corrections, <span class="hlt">ground-state</span> microscopic corrections, and nuclear <span class="hlt">ground-state</span> deformations of 9318 nuclei ranging from 16O to A=339. The calculations are based on the finite-range droplet macroscopic and the folded-Yukawa single-particle microscopic nuclear-structure models, which are completely specified. Relative to our FRDM(1992) mass table in Möller et al. (1995), the results are obtained in the same model, but with considerably improved treatment of deformation and fewer of the approximations that were necessary earlier, due to limitations in computer power. The more accurate execution of the model and the more extensivemore » and more accurate experimental mass data base now available allow us to determine one additional macroscopic-model parameter, the density-symmetry coefficient LL, which was not varied in the previous calculation, but set to zero. Because we now realize that the FRDM is inaccurate for some highly deformed shapes occurring in fission, because some effects are derived in terms of perturbations around a sphere, we only adjust its macroscopic parameters to <span class="hlt">ground-state</span> masses.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1248866','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1248866"><span>Nuclear <span class="hlt">ground-state</span> masses and deformations: FRDM(2012)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moller, P.; Sierk, A. J.; Ichikawa, T.; Sagawa, H.</p> <p>2016-03-25</p> <p>Here, we tabulate the atomic mass excesses and binding <span class="hlt">energies</span>, <span class="hlt">ground-state</span> shell-plus-pairing corrections, <span class="hlt">ground-state</span> microscopic corrections, and nuclear <span class="hlt">ground-state</span> deformations of 9318 nuclei ranging from <sup>16</sup>O to A=339. The calculations are based on the finite-range droplet macroscopic and the folded-Yukawa single-particle microscopic nuclear-structure models, which are completely specified. Relative to our FRDM(1992) mass table in Möller et al. (1995), the results are obtained in the same model, but with considerably improved treatment of deformation and fewer of the approximations that were necessary earlier, due to limitations in computer power. The more accurate execution of the model and the more extensive and more accurate experimental mass data base now available allow us to determine one additional macroscopic-model parameter, the density-symmetry coefficient LL, which was not varied in the previous calculation, but set to zero. Because we now realize that the FRDM is inaccurate for some highly deformed shapes occurring in fission, because some effects are derived in terms of perturbations around a sphere, we only adjust its macroscopic parameters to <span class="hlt">ground-state</span> masses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ADNDT.109....1M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ADNDT.109....1M"><span>Nuclear <span class="hlt">ground-state</span> masses and deformations: FRDM(2012)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Möller, P.; Sierk, A. J.; Ichikawa, T.; Sagawa, H.</p> <p>2016-05-01</p> <p>We tabulate the atomic mass excesses and binding <span class="hlt">energies</span>, <span class="hlt">ground-state</span> shell-plus-pairing corrections, <span class="hlt">ground-state</span> microscopic corrections, and nuclear <span class="hlt">ground-state</span> deformations of 9318 nuclei ranging from 16O to A = 339. The calculations are based on the finite-range droplet macroscopic and the folded-Yukawa single-particle microscopic nuclear-structure models, which are completely specified. Relative to our FRDM(1992) mass table in Möller et al. (1995), the results are obtained in the same model, but with considerably improved treatment of deformation and fewer of the approximations that were necessary earlier, due to limitations in computer power. The more accurate execution of the model and the more extensive and more accurate experimental mass data base now available allow us to determine one additional macroscopic-model parameter, the density-symmetry coefficient L, which was not varied in the previous calculation, but set to zero. Because we now realize that the FRDM is inaccurate for some highly deformed shapes occurring in fission, because some effects are derived in terms of perturbations around a sphere, we only adjust its macroscopic parameters to <span class="hlt">ground-state</span> masses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/166458','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/166458"><span><span class="hlt">Ground</span> <span class="hlt">states</span> of larger nuclei</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pieper, S.C.; Wiringa, R.B.; Pandharipande, V.R.</p> <p>1995-08-01</p> <p>The methods used for the few-body nuclei require operations on the complete spin-isospin vector; the size of this vector makes such methods impractical for nuclei with A > 8. During the last few years we developed cluster expansion methods that do not require operations on the complete vector. We use the same Hamiltonians as for the few-body nuclei and variational wave functions of form similar to the few-body wave functions. The cluster expansions are made for the noncentral parts of the wave functions and for the operators whose expectation values are being evaluated. The central pair correlations in the wave functions are treated exactly and this requires the evaluation of 3A-dimensional integrals which are done with Monte Carlo techniques. Most of our effort was on {sup 16}O, other p-shell nuclei, and {sup 40}Ca. In 1993 the Mathematics and Computer Science Division acquired a 128-processor IBM SP which has a theoretical peak speed of 16 Gigaflops (GFLOPS). We converted our program to run on this machine. Because of the large memory on each node of the SP, it was easy to convert the program to parallel form with very low communication overhead. Considerably more effort was needed to restructure the program from one oriented towards long vectors for the Cray computers at NERSC to one that makes efficient use of the cache of the RS6000 architecture. The SP made possible complete five-body cluster calculations of {sup 16}O for the first time; previously we could only do four-body cluster calculations. These calculations show that the expectation value of the two-body potential is converging less rapidly than we had thought, while that of the three-body potential is more rapidly convergent; the net result is no significant change to our predicted binding <span class="hlt">energy</span> for {sup 16}O using the new Argonne v{sub 18} potential and the Urbana IX three-nucleon potential. This result is in good agreement with experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..APR.T1028S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..APR.T1028S"><span>Achieving Higher <span class="hlt">Energies</span> via Passively Driven X-<span class="hlt">band</span> Structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sipahi, Taylan; Sipahi, Nihan; Milton, Stephen; Biedron, Sandra</p> <p>2014-03-01</p> <p>Due to their higher intrinsic shunt impedance X-<span class="hlt">band</span> accelerating structures significant gradients with relatively modest input powers, and this can lead to more compact particle accelerators. At the Colorado State University Accelerator Laboratory (CSUAL) we would like to adapt this technology to our 1.3 GHz L-<span class="hlt">band</span> accelerator system using a passively driven 11.7 GHz traveling wave X-<span class="hlt">band</span> configuration that capitalizes on the high shunt impedances achievable in X-<span class="hlt">band</span> accelerating structures in order to increase our overall beam <span class="hlt">energy</span> in a manner that does not require investment in an expensive, custom, high-power X-<span class="hlt">band</span> klystron system. Here we provide the design details of the X-<span class="hlt">band</span> structures that will allow us to achieve our goal of reaching the maximum practical net potential across the X-<span class="hlt">band</span> accelerating structure while driven solely by the beam from the L-<span class="hlt">band</span> system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvE..91d2128M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvE..91d2128M"><span><span class="hlt">Ground</span> <span class="hlt">states</span> for nonuniform periodic Ising chains</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martínez-Garcilazo, J. P.; Ramírez, C.</p> <p>2015-04-01</p> <p>We generalize Morita's works [J. Phys. A 7, 289 (1974), 10.1088/0305-4470/7/2/014; J. Phys. A 7, 1613 (1974), 10.1088/0305-4470/7/13/015] on <span class="hlt">ground</span> <span class="hlt">states</span> of Ising chains, for chains with a periodic structure and different spins, to any interaction order. The main assumption is translational invariance. The length of the irreducible blocks is a multiple of the period of the chain. If there is parity invariance, it restricts the length in general only in the diatomic case. There are degenerated states and under certain circumstances there could be nonregular <span class="hlt">ground</span> <span class="hlt">states</span>. We illustrate the results and give the <span class="hlt">ground</span> <span class="hlt">state</span> diagrams in several cases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhLA..380.3430M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhLA..380.3430M"><span><span class="hlt">Energy</span> <span class="hlt">bands</span> and gaps near an impurity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mihóková, E.; Schulman, L. S.</p> <p>2016-10-01</p> <p>It has been suggested that in the neighborhood of a certain kind of defect in a crystal there is a bend in the electronic <span class="hlt">band</span>. We confirm that this is indeed possible using the Kronig-Penney model. Our calculations also have implications for photonic crystals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20643876','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20643876"><span>Mimicking time evolution within a quantum <span class="hlt">ground</span> <span class="hlt">state</span>: <span class="hlt">Ground-state</span> quantum computation, cloning, and teleportation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mizel, Ari</p> <p>2004-07-01</p> <p><span class="hlt">Ground-state</span> quantum computers mimic quantum-mechanical time evolution within the amplitudes of a time-independent quantum state. We explore the principles that constrain this mimicking. A no-cloning argument is found to impose strong restrictions. It is shown, however, that there is flexibility that can be exploited using quantum teleportation methods to improve <span class="hlt">ground-state</span> quantum computer design.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPSJ...84g4701K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPSJ...84g4701K"><span>Absence of Magnetic Dipolar Phase Transition and Evolution of Low-<span class="hlt">Energy</span> Excitations in PrNb2Al20 with Crystal Electric Field Γ3 <span class="hlt">Ground</span> <span class="hlt">State</span>: Evidence from 93Nb-NQR Studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kubo, Tetsuro; Kotegawa, Hisashi; Tou, Hideki; Higashinaka, Ryuji; Nakama, Akihiro; Aoki, Yuji; Sato, Hideyuki</p> <p>2015-07-01</p> <p>We report measurements of bulk magnetic susceptibility and 93Nb nuclear quadrupole resonance (NQR) in the Pr-based caged compound PrNb2Al20. By analyzing the magnetic susceptibility and magnetization, the crystal electric field (CEF) level scheme of PrNb2Al20 is determined to be Γ3(0 K)-Γ4(21.32 K)-Γ5(43.98 K)-Γ1(51.16 K) within the framework of the localized 4f electron picture. The 93Nb-NQR spectra exhibit neither spectral broadening nor spectral shift upon cooling down to 75 mK. The 93Nb-NQR spin-lattice relaxation rate 1/T1 at 5 K depends on the frequency and remains almost constant below 5 K. The frequency dependence of 1/T1 is attributed to the magnetic fluctuation due to the hyperfine-enhanced 141Pr nuclear moment inherent in the nonmagnetic Γ3 CEF <span class="hlt">ground</span> <span class="hlt">state</span>. The present NQR results provide evidence that no symmetry-breaking magnetic dipole order occurs down to 75 mK. Also, considering an invariant form of the quadrupole and octupole couplings between a 93Nb nucleus and Pr 4f electrons, Pr 4f quadrupoles and an octupole can couple with a 93Nb nuclear quadrupole moment and nuclear spin, respectively. Together with the results of bulk measurements, the present NQR results suggest that the possibility of a static quadrupole or octupole ordering can be excluded down to 100 mK. At low temperatures below 500 mK, however, the nuclear spin-echo decay rate gradually increases and the decay curve changes from Gaussian decay to Lorentzian decay, suggesting the evolution of a low-<span class="hlt">energy</span> excitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvB..90q4104S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvB..90q4104S"><span>Efficient determination of alloy <span class="hlt">ground-state</span> structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seko, Atsuto; Shitara, Kazuki; Tanaka, Isao</p> <p>2014-11-01</p> <p>We propose an efficient approach to accurately finding the <span class="hlt">ground-state</span> structures in alloys based on the cluster expansion method. In this approach, a small number of candidate <span class="hlt">ground-state</span> structures are obtained without any information regarding the <span class="hlt">energy</span>. To generate the candidates, we employ the convex hull constructed from the correlation functions of all possible structures by using an efficient algorithm. This approach is applicable to not only simple lattices, but also complex lattices. First, we evaluate the convex hulls for binary alloys with four types of simple lattice. Then we discuss the structures on the vertices. To examine the accuracy of this approach, we perform a set of density functional theory calculations and the cluster expansion for the Ag-Au alloy and compare the formation <span class="hlt">energies</span> of the vertex structures with those of all possible structures. As applications, the <span class="hlt">ground-state</span> structures of the intermetallic compounds CuAu, CuAg, CuPd, AuAg, AuPd, AgPd, MoTa, MoW, and TaW are similarly evaluated. Finally, the <span class="hlt">energy</span> distribution is obtained for different cation arrangements in the MgAl2O4 spinel, for which long-range interactions are essential for the accurate description of its energetics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..DMP.P4001M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..DMP.P4001M"><span>Cavity optomechanics -- beyond the <span class="hlt">ground</span> <span class="hlt">state</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meystre, Pierre</p> <p>2011-05-01</p> <p>The coupling of coherent optical systems to micromechanical devices, combined with breakthroughs in nanofabrication and in ultracold science, has opened up the exciting new field of cavity optomechanics. Cooling of the vibrational motion of a broad range on oscillating cantilevers and mirrors near their <span class="hlt">ground</span> <span class="hlt">state</span> has been demonstrated, and the <span class="hlt">ground</span> <span class="hlt">state</span> of at least one such system has now been reached. Cavity optomechanics offers much promise in addressing fundamental physics questions and in applications such as the detection of feeble forces and fields, or the coherent control of AMO systems and of nanoscale electromechanical devices. However, these applications require taking cavity optomechanics ``beyond the <span class="hlt">ground</span> <span class="hlt">state</span>.'' This includes the generation and detection of squeezed and other non-classical states, the transfer of squeezing between electromagnetic fields and motional quadratures, and the development of measurement schemes for the characterization of nanomechanical structures. The talk will present recent ``beyond <span class="hlt">ground</span> <span class="hlt">state</span>'' developments in cavity optomechanics. We will show how the magnetic coupling between a mechanical membrane and a BEC - or between a mechanical tuning fork and a nanoscale cantilever - permits to control and monitor the center-of-mass position of the mechanical system, and will comment on the measurement back-action on the membrane motion. We will also discuss of state transfer between optical and microwave fields and micromechanical devices. Work done in collaboration with Dan Goldbaum, Greg Phelps, Keith Schwab, Swati Singh, Steve Steinke, Mehmet Tesgin, and Mukund Vengallatore and supported by ARO, DARPA, NSF, and ONR.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22482011','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22482011"><span>Room temperature skyrmion <span class="hlt">ground</span> <span class="hlt">state</span> stabilized through interlayer exchange coupling</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, Gong Schmid, Andreas K.; Mascaraque, Arantzazu; N'Diaye, Alpha T.</p> <p>2015-06-15</p> <p>Possible magnetic skyrmion device applications motivate the search for structures that extend the stability of skyrmion spin textures to ambient temperature. Here, we demonstrate an experimental approach to stabilize a room temperature skyrmion <span class="hlt">ground</span> <span class="hlt">state</span> in chiral magnetic films via exchange coupling across non-magnetic spacer layers. Using spin polarized low-<span class="hlt">energy</span> electron microscopy to measure all three Cartesian components of the magnetization vector, we image the spin textures in Fe/Ni films. We show how tuning the thickness of a copper spacer layer between chiral Fe/Ni films and perpendicularly magnetized Ni layers permits stabilization of a chiral stripe phase, a skyrmion phase, and a single domain phase. This strategy to stabilize skyrmion <span class="hlt">ground</span> <span class="hlt">states</span> can be extended to other magnetic thin film systems and may be useful for designing skyrmion based spintronics devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhST..165a4006N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhST..165a4006N"><span>Simulation of the hydrogen <span class="hlt">ground</span> <span class="hlt">state</span> in stochastic electrodynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nieuwenhuizen, Theo M.; Liska, Matthew T. P.</p> <p>2015-10-01</p> <p>Stochastic electrodynamics is a classical theory which assumes that the physical vacuum consists of classical stochastic fields with average <span class="hlt">energy</span> \\frac{1}{2}{{\\hslash }}ω in each mode, i.e., the zero-point Planck spectrum. While this classical theory explains many quantum phenomena related to harmonic oscillator problems, hard results on nonlinear systems are still lacking. In this work the hydrogen <span class="hlt">ground</span> <span class="hlt">state</span> is studied by numerically solving the Abraham-Lorentz equation in the dipole approximation. First the stochastic Gaussian field is represented by a sum over Gaussian frequency components, next the dynamics is solved numerically using OpenCL. The approach improves on work by Cole and Zou 2003 by treating the full 3d problem and reaching longer simulation times. The results are compared with a conjecture for the <span class="hlt">ground</span> <span class="hlt">state</span> phase space density. Though short time results suggest a trend towards confirmation, in all attempted modellings the atom ionises at longer times.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1132327','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1132327"><span>Alternative <span class="hlt">ground</span> <span class="hlt">states</span> enable pathway switching in biological electron transfer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Abriata, Luciano A.; Alvarez-Paggi, Damian; Ledesma, Gabirela N.; Blackburn, Ninian J.; Vila, Alejandro J.; Murgida, Daniel H.</p> <p>2012-10-10</p> <p>Electron transfer is the simplest chemical reaction and constitutes the basis of a large variety of biological processes, such as photosynthesis and cellular respiration. Nature has evolved specific proteins and cofactors for these functions. The mechanisms optimizing biological electron transfer have been matter of intense debate, such as the role of the protein milieu between donor and acceptor sites. Here we propose a mechanism regulating long-range electron transfer in proteins. Specifically, we report a spectroscopic, electrochemical, and theoretical study on WT and single-mutant CuA redox centers from Thermus thermophilus, which shows that thermal fluctuations may populate two alternative <span class="hlt">ground-state</span> electronic wave functions optimized for electron entry and exit, respectively, through two different and nearly perpendicular pathways. In conclusion, these findings suggest a unique role for alternative or “invisible” electronic <span class="hlt">ground</span> <span class="hlt">states</span> in directional electron transfer. Moreover, it is shown that this <span class="hlt">energy</span> gap and, therefore, the equilibrium between <span class="hlt">ground</span> <span class="hlt">states</span> can be fine-tuned by minor perturbations, suggesting alternative ways through which protein–protein interactions and membrane potential may optimize and regulate electron–proton <span class="hlt">energy</span> transduction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1132327-alternative-ground-states-enable-pathway-switching-biological-electron-transfer','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1132327-alternative-ground-states-enable-pathway-switching-biological-electron-transfer"><span>Alternative <span class="hlt">ground</span> <span class="hlt">states</span> enable pathway switching in biological electron transfer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Abriata, Luciano A.; Alvarez-Paggi, Damian; Ledesma, Gabirela N.; ...</p> <p>2012-10-10</p> <p>Electron transfer is the simplest chemical reaction and constitutes the basis of a large variety of biological processes, such as photosynthesis and cellular respiration. Nature has evolved specific proteins and cofactors for these functions. The mechanisms optimizing biological electron transfer have been matter of intense debate, such as the role of the protein milieu between donor and acceptor sites. Here we propose a mechanism regulating long-range electron transfer in proteins. Specifically, we report a spectroscopic, electrochemical, and theoretical study on WT and single-mutant CuA redox centers from Thermus thermophilus, which shows that thermal fluctuations may populate two alternative <span class="hlt">ground-state</span> electronicmore » wave functions optimized for electron entry and exit, respectively, through two different and nearly perpendicular pathways. In conclusion, these findings suggest a unique role for alternative or “invisible” electronic <span class="hlt">ground</span> <span class="hlt">states</span> in directional electron transfer. Moreover, it is shown that this <span class="hlt">energy</span> gap and, therefore, the equilibrium between <span class="hlt">ground</span> <span class="hlt">states</span> can be fine-tuned by minor perturbations, suggesting alternative ways through which protein–protein interactions and membrane potential may optimize and regulate electron–proton <span class="hlt">energy</span> transduction.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3491497','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3491497"><span>Alternative <span class="hlt">ground</span> <span class="hlt">states</span> enable pathway switching in biological electron transfer</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Abriata, Luciano A.; Álvarez-Paggi, Damián; Ledesma, Gabriela N.; Blackburn, Ninian J.; Vila, Alejandro J.; Murgida, Daniel H.</p> <p>2012-01-01</p> <p>Electron transfer is the simplest chemical reaction and constitutes the basis of a large variety of biological processes, such as photosynthesis and cellular respiration. Nature has evolved specific proteins and cofactors for these functions. The mechanisms optimizing biological electron transfer have been matter of intense debate, such as the role of the protein milieu between donor and acceptor sites. Here we propose a mechanism regulating long-range electron transfer in proteins. Specifically, we report a spectroscopic, electrochemical, and theoretical study on WT and single-mutant CuA redox centers from Thermus thermophilus, which shows that thermal fluctuations may populate two alternative <span class="hlt">ground-state</span> electronic wave functions optimized for electron entry and exit, respectively, through two different and nearly perpendicular pathways. These findings suggest a unique role for alternative or “invisible” electronic <span class="hlt">ground</span> <span class="hlt">states</span> in directional electron transfer. Moreover, it is shown that this <span class="hlt">energy</span> gap and, therefore, the equilibrium between <span class="hlt">ground</span> <span class="hlt">states</span> can be fine-tuned by minor perturbations, suggesting alternative ways through which protein–protein interactions and membrane potential may optimize and regulate electron–proton <span class="hlt">energy</span> transduction. PMID:23054836</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23054836','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23054836"><span>Alternative <span class="hlt">ground</span> <span class="hlt">states</span> enable pathway switching in biological electron transfer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abriata, Luciano A; Álvarez-Paggi, Damián; Ledesma, Gabriela N; Blackburn, Ninian J; Vila, Alejandro J; Murgida, Daniel H</p> <p>2012-10-23</p> <p>Electron transfer is the simplest chemical reaction and constitutes the basis of a large variety of biological processes, such as photosynthesis and cellular respiration. Nature has evolved specific proteins and cofactors for these functions. The mechanisms optimizing biological electron transfer have been matter of intense debate, such as the role of the protein milieu between donor and acceptor sites. Here we propose a mechanism regulating long-range electron transfer in proteins. Specifically, we report a spectroscopic, electrochemical, and theoretical study on WT and single-mutant Cu(A) redox centers from Thermus thermophilus, which shows that thermal fluctuations may populate two alternative <span class="hlt">ground-state</span> electronic wave functions optimized for electron entry and exit, respectively, through two different and nearly perpendicular pathways. These findings suggest a unique role for alternative or "invisible" electronic <span class="hlt">ground</span> <span class="hlt">states</span> in directional electron transfer. Moreover, it is shown that this <span class="hlt">energy</span> gap and, therefore, the equilibrium between <span class="hlt">ground</span> <span class="hlt">states</span> can be fine-tuned by minor perturbations, suggesting alternative ways through which protein-protein interactions and membrane potential may optimize and regulate electron-proton <span class="hlt">energy</span> transduction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21715909','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21715909"><span>Computational schemes for the <span class="hlt">ground-state</span> pair density.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Higuchi, K; Higuchi, M</p> <p>2009-02-11</p> <p>We reconfirm the performance of the initial scheme for calculating the <span class="hlt">ground-state</span> pair density (Higuchi and Higuchi 2007 Physica B 387 117, 2008 Phys. Rev. B 78 125101) by using the alternative approximation of the correlating kinetic <span class="hlt">energy</span> functional. It is shown that about 20% of the correlation <span class="hlt">energy</span> can be reproduced by the initial scheme, irrespective of the approximate form of the correlating kinetic <span class="hlt">energy</span> functional. On the basis of the initial scheme, various kinds of schemes that go beyond the initial one can be developed. We illustrate two kinds of computational schemes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017QS%26T....2a5005K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017QS%26T....2a5005K"><span>Local reversibility and entanglement structure of many-body <span class="hlt">ground</span> <span class="hlt">states</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuwahara, Tomotaka; Arad, Itai; Amico, Luigi; Vedral, Vlatko</p> <p>2017-03-01</p> <p>The low-temperature physics of quantum many-body systems is largely governed by the structure of their <span class="hlt">ground</span> <span class="hlt">states</span>. Minimizing the <span class="hlt">energy</span> of local interactions, <span class="hlt">ground</span> <span class="hlt">states</span> often reflect strong properties of locality such as the area law for entanglement entropy and the exponential decay of correlations between spatially separated observables. Here, we present a novel characterization of quantum states, which we call ‘local reversibility’. It characterizes the type of operations that are needed to reverse the action of a general disturbance on the state. We prove that unique <span class="hlt">ground</span> <span class="hlt">states</span> of gapped local Hamiltonian are locally reversible. This way, we identify new universal features of many-body <span class="hlt">ground</span> <span class="hlt">states</span>, which cannot be derived from the aforementioned properties. We use local reversibility to distinguish between states enjoying microscopic and macroscopic quantum phenomena. To demonstrate the potential of our approach, we prove specific properties of <span class="hlt">ground</span> <span class="hlt">states</span>, which are relevant both to critical and non-critical theories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5886354','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5886354"><span>Off-diagonal long-range order (ODLRO) and <span class="hlt">ground</span> <span class="hlt">state</span> properties of liquid helium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rodriguez-Gomez, J.R.</p> <p>1983-01-01</p> <p>An independent calculation of the condensate fraction and the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span> of liquid helium is given. The Froehlich ansatz for the second reduced density matrix in conjunction with the ODLORO hypothesis for liquid helium below the critical temperature is used. Froehlich's ansatz is shown to be consistent with numerical calculations of the <span class="hlt">ground</span> <span class="hlt">state</span> properties of liquid helium. The <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span> was -5.10/sup 0/K, close to the experimental value. The condensate fraction turned out to be about 10% which is within the margin of error of recent neutron scattering experiments and agrees with other theoretical calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MPLB...3050402W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MPLB...3050402W"><span>The <span class="hlt">energy</span> <span class="hlt">band</span> structure of Si and Ge nanolayers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Xueke; Huang, Weiqi; Huang, Zhongmei; Qin, Chaojie; Tang, Yanlin</p> <p>2016-12-01</p> <p>First-principles calculation based on density functional theory (DFT) with the generalized gradient approximation (GGA) were carried out to investigate the <span class="hlt">energy</span> <span class="hlt">band</span> gap structure of Si and Ge nanofilms. Calculation results show that the <span class="hlt">band</span> gaps of Si(111) and Ge(110) nanofilms are indirect structures and independent of film thickness, the <span class="hlt">band</span> gaps of Si(110) and Ge(100) nanofilms could be transfered into the direct structure for nanofilm thickness of less than a certain value, and the <span class="hlt">band</span> gaps of Si(100) and Ge(111) nanofilms are the direct structures in the present model thickness range (about 7 nm). Moreover, the changes of the <span class="hlt">band</span> gaps on the Si and Ge nanofilms follow the quantum confinement effects. It will be a good way to obtain direct <span class="hlt">band</span> gap emission in Si and Ge materials, and to develop Si and Ge laser on Si chip.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780049291&hterms=Hcp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DHcp','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780049291&hterms=Hcp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DHcp"><span><span class="hlt">Ground-state</span> properties of hcp helium-4 on the basis of a cell model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jacobi, N.; Zmuidzinas, J. S.</p> <p>1977-01-01</p> <p>A simple cell model is used to compute the <span class="hlt">ground-state</span> <span class="hlt">energy</span> and the volume-pressure relation for hcp He-4, in good agreement with experiments and with more sophisticated quantum mechanical calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780049291&hterms=Properties+Helium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DProperties%2BHelium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780049291&hterms=Properties+Helium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DProperties%2BHelium"><span><span class="hlt">Ground-state</span> properties of hcp helium-4 on the basis of a cell model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jacobi, N.; Zmuidzinas, J. S.</p> <p>1977-01-01</p> <p>A simple cell model is used to compute the <span class="hlt">ground-state</span> <span class="hlt">energy</span> and the volume-pressure relation for hcp He-4, in good agreement with experiments and with more sophisticated quantum mechanical calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPCM...28a6001K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPCM...28a6001K"><span><span class="hlt">Ground</span> <span class="hlt">state</span> magnetic response of two coupled dodecahedra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Konstantinidis, N. P.</p> <p>2016-01-01</p> <p>The antiferromagnetic Heisenberg model on the dodecahedron possesses a number of <span class="hlt">ground</span> <span class="hlt">state</span> magnetization discontinuities in a field at the classical and quantum level, even though it lacks magnetic anisotropy. Here the model is considered for two dodecahedra coupled antiferromagnetically along one of their faces, as a first step to determine the magnetic response of collections of fullerene molecules. The magnetic response is determined from the competition among the intra-, interdodecahedral exchange and magnetic field <span class="hlt">energies</span>. At the classical level the discontinuities of the isolated dodecahedron are renormalized by the interdodecahedral coupling, while new ones show up, with the maximum number of <span class="hlt">ground</span> <span class="hlt">state</span> discontinuities being six for a specific range of the coupling. In the full quantum limit where the individual spin magnitude s=\\frac{1}{2} , there are two <span class="hlt">ground</span> <span class="hlt">state</span> discontinuities originating in the single discontinuity of the isolated dodecahedron, and another one due to the intermolecular coupling, generating a total of three discontinuities which come one right after the other. These results show that the magnetic response of more than one dodecahedra interacting together is quite richer than the one of a single dodecahedron.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26643035','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26643035"><span><span class="hlt">Ground</span> <span class="hlt">state</span> magnetic response of two coupled dodecahedra.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Konstantinidis, N P</p> <p>2016-01-13</p> <p>The antiferromagnetic Heisenberg model on the dodecahedron possesses a number of <span class="hlt">ground</span> <span class="hlt">state</span> magnetization discontinuities in a field at the classical and quantum level, even though it lacks magnetic anisotropy. Here the model is considered for two dodecahedra coupled antiferromagnetically along one of their faces, as a first step to determine the magnetic response of collections of fullerene molecules. The magnetic response is determined from the competition among the intra-, interdodecahedral exchange and magnetic field <span class="hlt">energies</span>. At the classical level the discontinuities of the isolated dodecahedron are renormalized by the interdodecahedral coupling, while new ones show up, with the maximum number of <span class="hlt">ground</span> <span class="hlt">state</span> discontinuities being six for a specific range of the coupling. In the full quantum limit where the individual spin magnitude [Formula: see text], there are two <span class="hlt">ground</span> <span class="hlt">state</span> discontinuities originating in the single discontinuity of the isolated dodecahedron, and another one due to the intermolecular coupling, generating a total of three discontinuities which come one right after the other. These results show that the magnetic response of more than one dodecahedra interacting together is quite richer than the one of a single dodecahedron.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21408143','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21408143"><span>Speed of Markovian relaxation toward the <span class="hlt">ground</span> <span class="hlt">state</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vogl, Malte; Schaller, Gernot; Brandes, Tobias</p> <p>2010-01-15</p> <p>For sufficiently low reservoir temperatures, it is known that open quantum systems subject to decoherent interactions with the reservoir relax toward their <span class="hlt">ground</span> <span class="hlt">state</span> in the weak coupling limit. Within the framework of quantum master equations, this is formalized by the Born-Markov-secular (BMS) approximation, where one obtains the system Gibbs state with the reservoir temperature as a stationary state. When the solution to some problem is encoded in the (isolated) <span class="hlt">ground</span> <span class="hlt">state</span> of a system Hamiltonian, decoherence can therefore be exploited for computation. The computational complexity is then given by the scaling of the relaxation time with the system size n. We study the relaxation behavior for local and nonlocal Hamiltonians that are coupled dissipatively with local and nonlocal operators to a bosonic bath in thermal equilibrium. We find that relaxation is generally more efficient when coherences of the density matrix in the system <span class="hlt">energy</span> eigenbasis are taken into account. In addition, the relaxation speed strongly depends on the matrix elements of the coupling operators between initial state and <span class="hlt">ground</span> <span class="hlt">state</span>. We show that Dicke superradiance is a special case of our relaxation models and can thus be understood as a coherence-assisted relaxation speedup.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24237558','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24237558"><span>Striped spin liquid crystal <span class="hlt">ground</span> <span class="hlt">state</span> instability of kagome antiferromagnets.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Clark, Bryan K; Kinder, Jesse M; Neuscamman, Eric; Chan, Garnet Kin-Lic; Lawler, Michael J</p> <p>2013-11-01</p> <p>The Dirac spin liquid <span class="hlt">ground</span> <span class="hlt">state</span> of the spin 1/2 Heisenberg kagome antiferromagnet has potential instabilities. This has been suggested as the reason why it does not emerge as the <span class="hlt">ground</span> <span class="hlt">state</span> in large-scale numerical calculations. However, previous attempts to observe these instabilities have failed. We report on the discovery of a projected BCS state with lower <span class="hlt">energy</span> than the projected Dirac spin liquid state which provides new insight into the stability of the <span class="hlt">ground</span> <span class="hlt">state</span> of the kagome antiferromagnet. The new state has three remarkable features. First, it breaks spatial symmetry in an unusual way that may leave spinons deconfined along one direction. Second, it breaks the U(1) gauge symmetry down to Z(2). Third, it has the spatial symmetry of a previously proposed "monopole" suggesting that it is an instability of the Dirac spin liquid. The state described herein also shares a remarkable similarity to the distortion of the kagome lattice observed at low Zn concentrations in Zn-paratacamite and in recently grown single crystals of volborthite suggesting it may already be realized in these materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25396366','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25396366"><span>Trapping cold <span class="hlt">ground</span> <span class="hlt">state</span> argon atoms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Edmunds, P D; Barker, P F</p> <p>2014-10-31</p> <p>We trap cold, <span class="hlt">ground</span> <span class="hlt">state</span> argon atoms in a deep optical dipole trap produced by a buildup cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the <span class="hlt">ground</span> <span class="hlt">state</span> atoms cannot be directly probed, we detect them by observing the collisional loss of cotrapped metastable argon atoms and determine an elastic cross section. Using a type of parametric loss spectroscopy we also determine the polarizability of the metastable 4s[3/2](2) state to be (7.3±1.1)×10(-39)  C m(2)/V. Finally, Penning and associative losses of metastable atoms in the absence of light assisted collisions, are determined to be (3.3±0.8)×10(-10)  cm(3) s(-1).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DMP.Q1207S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DMP.Q1207S"><span>Individual Atoms in their Quantum <span class="hlt">Ground</span> <span class="hlt">State</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schwartz, Eyal; Sompet, Pimonpan; Fung, Yin Hsien; Andersen, Mikkel F.</p> <p>2016-05-01</p> <p>An ultimate control of pure quantum states is an excellent platform for various quantum science and engineering. In this work, we perform quantum manipulation of individual Rubidium atoms in a tightly focus optical tweezer in order to cool them into their vibrational <span class="hlt">ground</span> <span class="hlt">state</span> via Raman sideband cooling. Our experimental scheme involves a combination of Raman sideband transitions and optical pumping of the atoms that couples two magnetic field sublevels indifferent to magnetic noise thus providing a much longer atomic coherence time compared to previous cooling schemes. By installing most of the atoms in their <span class="hlt">ground</span> <span class="hlt">state</span>, we managed to achieve two-dimensional cooling on the way to create a full nil entropy quantum state of single atoms and single molecules. We acknowledge the Marsden Fund, CORE and DWC for their support.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JChPh.145s4302Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JChPh.145s4302Z"><span>Electronic <span class="hlt">ground</span> <span class="hlt">state</span> of Ni2+</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zamudio-Bayer, V.; Lindblad, R.; Bülow, C.; Leistner, G.; Terasaki, A.; v. Issendorff, B.; Lau, J. T.</p> <p>2016-11-01</p> <p>The 9/2 4Φ <span class="hlt">ground</span> <span class="hlt">state</span> of the Ni2+ diatomic molecular cation is determined experimentally from temperature and magnetic-field-dependent x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap, where an electronic and rotational temperature of 7.4 ±0.2 K was reached by buffer gas cooling of the molecular ion. The contribution of the spin dipole operator to the x-ray magnetic circular dichroism spin sum rule amounts to 7 Tz =0.17 ± 0.06 μB per atom, approximately 11% of the spin magnetic moment. We find that, in general, homonuclear diatomic molecular cations of 3d transition metals seem to adopt maximum spin magnetic moments in their electronic <span class="hlt">ground</span> <span class="hlt">states</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760054325&hterms=property+liquids&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dproperty%2Bof%2Bliquids','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760054325&hterms=property+liquids&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dproperty%2Bof%2Bliquids"><span><span class="hlt">Ground</span> <span class="hlt">state</span> properties of solid and liquid spin-aligned atomic hydrogen</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Danilowicz, R. L.; Dugan, J. V., Jr.; Etters, R. D.</p> <p>1976-01-01</p> <p>Calculations of the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span> in the solid phase were performed with the aid of a variational approach. The Morse potential form of the atomic triple potential computed by Kolos and Wolniewicz (1965) was employed for the calculations. The <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energies</span> of both the liquid and solid phases of spin-aligned atomic hydrogen around the volume of the transition are presented in a graph.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20861016','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20861016"><span>Global Calculations of <span class="hlt">Ground-State</span> Axial Shape Asymmetry of Nuclei</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moeller, Peter; Bengtsson, Ragnar; Carlsson, B. Gillis; Olivius, Peter; Ichikawa, Takatoshi</p> <p>2006-10-20</p> <p>Important insight into the symmetry properties of the nuclear <span class="hlt">ground-state</span> (gs) shape is obtained from the characteristics of low-lying collective <span class="hlt">energy</span>-level spectra. In the 1950s, experimental and theoretical studies showed that in the gs many nuclei are spheroidal in shape rather than spherical. Later, a hexadecapole component of the gs shape was identified. In the 1970-1995 time frame, a consensus that reflection symmetry of the gs shape was broken for some nuclei emerged. Here we present the first calculation across the nuclear chart of axial symmetry breaking in the nuclear gs. We show that we fulfill a necessary condition: Where we calculate axial symmetry breaking, characteristic gamma <span class="hlt">bands</span> are observed experimentally. Moreover, we find that, for those nuclei where axial asymmetry is found, a systematic deviation between calculated and measured masses is removed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJT....37..108S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJT....37..108S"><span><span class="hlt">Energy</span> <span class="hlt">Bands</span> and Thermoelectricity of Filled Skutterudite EuRu4As_{12}</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shankar, A.; Rai, D. P.; Sandeep; Khenata, R.; Thapa, R. K.; Mandal, P. K.</p> <p>2016-11-01</p> <p>Density functional theory-based calculations of the elastic and electronic properties with magnetic moments of the filled skutterudite EuRu4As_{12} have been performed in its ferromagnetic <span class="hlt">ground</span> <span class="hlt">state</span>. The full-potential linearized augmented plane wave (FP-LAPW) method has been used for the study presented here. The numerical values of the elastic parameters are estimated within the framework of the Voigt-Reuss-Hill approximations. The <span class="hlt">energy</span> <span class="hlt">band</span> structure calculation performed near the Fermi <span class="hlt">energy</span> level shows the metallic nature of the material with a high value of Seebeck coefficient ( S). The presence of an exchange splitting of Eu-4 f states suggests their appreciable contribution toward the magnetic behavior. The analysis of the thermal transport properties confirms the result obtained from the electronic structure calculation with Seebeck coefficient of 118 μ{V/K} and the figure of merit ( ZT) value of 0.51, at room temperature. The estimated values of S and ZT indicate the possibility of the thermoelectric applications of the sample material.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23412433','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23412433"><span>Potential <span class="hlt">energy</span> surfaces for ground and excited electronic states of the CF3I molecule and their relevance to its A-<span class="hlt">band</span> photodissociation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alekseyev, Aleksey B; Liebermann, Heinz-Peter; Buenker, Robert J</p> <p>2013-05-14</p> <p>The multireference spin-orbit (SO) configuration interaction (CI) method in its Λ-S contracted SO-CI version is employed to calculate two-dimensional potential <span class="hlt">energy</span> surfaces for the ground and low-lying excited states of CF3I relevant to its photodissociation in the lowest absorption <span class="hlt">band</span> (A <span class="hlt">band</span>). The computed equilibrium geometry for the X̃A1 <span class="hlt">ground</span> <span class="hlt">state</span> and vibrational frequency ν3 for the C-I stretch mode agree well with available experimental data. The (3)Q0(+) state dissociating to the excited I((2)P1/2) limit is found to have a minimum of 1570 cm(-1) significantly shifted to larger internuclear distances (RC-I = 5.3 a0) relative to the <span class="hlt">ground</span> <span class="hlt">state</span>. Similar to the CH3I case, this makes a single-exponent approximation commonly employed for analysis of the CF3I recoil dynamics unsuitable. The 4E((3)A1) state possessing an allowed transition from the <span class="hlt">ground</span> <span class="hlt">state</span> and converging to the same atomic limit as (3)Q0(+) is calculated to lie too high in the Franck-Condon region to have any significant impact on the A-<span class="hlt">band</span> absorption. The computed vertical excitation <span class="hlt">energies</span> for the (3)Q1, (3)Q0(+), and (1)Q states indicate that the A-<span class="hlt">band</span> spectrum must lie approximately between 31,300 and 45,200 cm(-1), i.e., between 220 and 320 nm. This result is in very good agreement with the measured absorption spectrum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4827494','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4827494"><span>Tuning the <span class="hlt">Ground</span> <span class="hlt">State</span> Symmetry of Acetylenyl Radicals</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2015-01-01</p> <p>The lowest excited state of the acetylenyl radical, HCC, is a 2Π state, only 0.46 eV above the <span class="hlt">ground</span> <span class="hlt">state</span>, 2Σ+. The promotion of an electron from a π bond pair to a singly occupied σ hybrid orbital is all that is involved, and so we set out to tune those orbital <span class="hlt">energies</span>, and with them the relative energetics of 2Π and 2Σ+ states. A strategy of varying ligand electronegativity, employed in a previous study on substituted carbynes, RC, was useful, but proved more difficult to apply for substituted acetylenyl radicals, RCC. However, π-donor/acceptor substitution is effective in modifying the state <span class="hlt">energies</span>. We are able to design molecules with 2Π <span class="hlt">ground</span> <span class="hlt">states</span> (NaOCC, H2NCC (2A″), HCSi, FCSi, etc.) and vary the 2Σ+–2Π <span class="hlt">energy</span> gap over a 4 eV range. We find an inconsistency between bond order and bond dissociation <span class="hlt">energy</span> measures of the bond strength in the Si-containing molecules; we provide an explanation through an analysis of the relevant potential <span class="hlt">energy</span> curves. PMID:27162981</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPA....6c5306Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPA....6c5306Z"><span>The significant role of covalency in determining the <span class="hlt">ground</span> <span class="hlt">state</span> of cobalt phthalocyanines molecule</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Jing; Zhang, Linjuan; Hu, Zhiwei; Kuo, Changyang; Liu, Hengjie; Lin, Xiao; Wang, Yu; Pi, Tun-Wen; Wang, Jianqiang; Zhang, Shuo</p> <p>2016-03-01</p> <p>To shed some light on the metal 3d <span class="hlt">ground</span> <span class="hlt">state</span> configuration of cobalt phthalocyanines system, so far in debate, we present an investigation by X-ray absorption spectroscopy (XAS) at Co L2,3 edge and theoretical calculation. The density functional theory calculations reveal highly anisotropic covalent bond between central cobalt ion and nitrogen ligands, with the dominant σ donor accompanied by weak π-back acceptor interaction. Our combined experimental and theoretical study on the Co-L2,3 XAS spectra demonstrate a robust <span class="hlt">ground</span> <span class="hlt">state</span> of 2A1g symmetry that is built from 73% 3d7 character and 27% 3 d 8 L ¯ ( L ¯ denotes a ligand hole) components, as the first excited-state with 2Eg symmetry lies about 158 meV higher in <span class="hlt">energy</span>. The effect of anisotropic and isotropic covalency on the <span class="hlt">ground</span> <span class="hlt">state</span> was also calculated and the results indicate that the <span class="hlt">ground</span> <span class="hlt">state</span> with 2A1g symmetry is robust in a large range of anisotropic covalent strength while a transition of <span class="hlt">ground</span> <span class="hlt">state</span> from 2A1g to 2Eg configuration when isotropic covalent strength increases to a certain extent. Here, we address a significant anisotropic covalent effect of short Co(II)-N bond on the <span class="hlt">ground</span> <span class="hlt">state</span> and suggest that it should be taken into account in determining the <span class="hlt">ground</span> <span class="hlt">state</span> of analogous cobalt complexes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21352380','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21352380"><span>Two-electron photoionization of <span class="hlt">ground-state</span> lithium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kheifets, A. S.; Fursa, D. V.; Bray, I.</p> <p>2009-12-15</p> <p>We apply the convergent close-coupling (CCC) formalism to single-photon two-electron ionization of the lithium atom in its <span class="hlt">ground</span> <span class="hlt">state</span>. We treat this reaction as single-electron photon absorption followed by inelastic scattering of the photoelectron on a heliumlike Li{sup +} ion. The latter scattering process can be described accurately within the CCC formalism. We obtain integrated cross sections of single photoionization leading to the ground and various excited states of the Li{sup +} ion as well as double photoionization extending continuously from the threshold to the asymptotic limit of infinite photon <span class="hlt">energy</span>. Comparison with available experimental and theoretical data validates the CCC model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22068763','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22068763"><span><span class="hlt">Ground</span> <span class="hlt">state</span> of a resonantly interacting Bose gas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Diederix, J. M.; Heijst, T. C. F. van; Stoof, H. T. C.</p> <p>2011-09-15</p> <p>We show that a two-channel mean-field theory for a Bose gas near a Feshbach resonance allows for an analytic computation of the chemical potential, and therefore the universal constant {beta}, at unitarity. To improve on this mean-field theory, which physically neglects condensate depletion, we study a variational Jastrow ansatz for the <span class="hlt">ground-state</span> wave function and use the hypernetted-chain approximation to minimize the <span class="hlt">energy</span> for all positive values of the scattering length. We also show that other important physical quantities such as Tan's contact and the condensate fraction can be directly obtained from this approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhRvL.108j2501S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhRvL.108j2501S"><span>First Observation of <span class="hlt">Ground</span> <span class="hlt">State</span> Dineutron Decay: Be16</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spyrou, A.; Kohley, Z.; Baumann, T.; Bazin, D.; Brown, B. A.; Christian, G.; Deyoung, P. A.; Finck, J. E.; Frank, N.; Lunderberg, E.; Mosby, S.; Peters, W. A.; Schiller, A.; Smith, J. K.; Snyder, J.; Strongman, M. J.; Thoennessen, M.; Volya, A.</p> <p>2012-03-01</p> <p>We report on the first observation of dineutron emission in the decay of Be16. A single-proton knockout reaction from a 53MeV/u B17 beam was used to populate the <span class="hlt">ground</span> <span class="hlt">state</span> of Be16. Be16 is bound with respect to the emission of one neutron and unbound to two-neutron emission. The dineutron character of the decay is evidenced by a small emission angle between the two neutrons. The two-neutron separation <span class="hlt">energy</span> of Be16 was measured to be 1.35(10) MeV, in good agreement with shell model calculations, using standard interactions for this mass region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006APS..MARH35004W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006APS..MARH35004W"><span>Mapping the Copper <span class="hlt">energy</span> <span class="hlt">band</span> using the quantum well states</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, J.; Choi, J.; Owens, T.; Qiu, Z. Q.; Rotenberg, E.; Smith, N. V.</p> <p>2006-03-01</p> <p>Quantum well states (QWS) of copper electrons in Cu/Co/Cu(100) system are investigated using Angle Resolved Photoemission Electron Spectroscopy (ARPES). The samples were grown epitaxially at room temperature and measured in situ at beamlime 7 of the Advanced Light Source (ALS). Photoemission intensity oscillates with both the electron <span class="hlt">energy</span> and the Cu film thickness. By counting the thickness oscillation periodicity at a given <span class="hlt">energy</span>, we can determine the out-of-plane electron momentum without the need of the phase value in the phase accumulation model. This allows the experimental determination of the E-k relation (<span class="hlt">energy</span> <span class="hlt">band</span>) for the Cu film. We here report the Cu <span class="hlt">energy</span> <span class="hlt">band</span> determined in this way at different in-plane momentum. In addition, by fitting the oscillation as a function of the Cu thickness, we also determined the phase value of the quantization condition as a function of the <span class="hlt">energy</span> and in-plane momentum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4555038','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4555038"><span>Quantitative analysis on electric dipole <span class="hlt">energy</span> in Rashba <span class="hlt">band</span> splitting</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hong, Jisook; Rhim, Jun-Won; Kim, Changyoung; Ryong Park, Seung; Hoon Shim, Ji</p> <p>2015-01-01</p> <p>We report on quantitative comparison between the electric dipole <span class="hlt">energy</span> and the Rashba <span class="hlt">band</span> splitting in model systems of Bi and Sb triangular monolayers under a perpendicular electric field. We used both first-principles and tight binding calculations on p-orbitals with spin-orbit coupling. First-principles calculation shows Rashba <span class="hlt">band</span> splitting in both systems. It also shows asymmetric charge distributions in the Rashba split <span class="hlt">bands</span> which are induced by the orbital angular momentum. We calculated the electric dipole <span class="hlt">energies</span> from coupling of the asymmetric charge distribution and external electric field, and compared it to the Rashba splitting. Remarkably, the total split <span class="hlt">energy</span> is found to come mostly from the difference in the electric dipole <span class="hlt">energy</span> for both Bi and Sb systems. A perturbative approach for long wave length limit starting from tight binding calculation also supports that the Rashba <span class="hlt">band</span> splitting originates mostly from the electric dipole <span class="hlt">energy</span> difference in the strong atomic spin-orbit coupling regime. PMID:26323493</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26588541','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26588541"><span>Derivation of the RPA (Random Phase Approximation) Equation of ATDDFT (Adiabatic Time Dependent Density Functional <span class="hlt">Ground</span> <span class="hlt">State</span> Response Theory) from an Excited State Variational Approach Based on the <span class="hlt">Ground</span> <span class="hlt">State</span> Functional.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ziegler, Tom; Krykunov, Mykhaylo; Autschbach, Jochen</p> <p>2014-09-09</p> <p>The random phase approximation (RPA) equation of adiabatic time dependent density functional <span class="hlt">ground</span> <span class="hlt">state</span> response theory (ATDDFT) has been used extensively in studies of excited states. It extracts information about excited states from frequency dependent <span class="hlt">ground</span> <span class="hlt">state</span> response properties and avoids, thus, in an elegant way, direct Kohn-Sham calculations on excited states in accordance with the status of DFT as a <span class="hlt">ground</span> <span class="hlt">state</span> theory. Thus, excitation <span class="hlt">energies</span> can be found as resonance poles of frequency dependent <span class="hlt">ground</span> <span class="hlt">state</span> polarizability from the eigenvalues of the RPA equation. ATDDFT is approximate in that it makes use of a frequency independent <span class="hlt">energy</span> kernel derived from the <span class="hlt">ground</span> <span class="hlt">state</span> functional. It is shown in this study that one can derive the RPA equation of ATDDFT from a purely variational approach in which stationary states above the <span class="hlt">ground</span> <span class="hlt">state</span> are located using our constricted variational DFT (CV-DFT) method and the <span class="hlt">ground</span> <span class="hlt">state</span> functional. Thus, locating stationary states above the <span class="hlt">ground</span> <span class="hlt">state</span> due to one-electron excitations with a <span class="hlt">ground</span> <span class="hlt">state</span> functional is completely equivalent to solving the RPA equation of TDDFT employing the same functional. The present study is an extension of a previous work in which we demonstrated the equivalence between ATDDFT and CV-DFT within the Tamm-Dancoff approximation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.T33C2433S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.T33C2433S"><span>Propagation <span class="hlt">Energies</span> Inferred from Deformation <span class="hlt">Bands</span> in Sandstone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schultz, R. A.; Soliva, R.</p> <p>2011-12-01</p> <p>The J-integral is used to calculate the <span class="hlt">band</span> propagation <span class="hlt">energies</span> Jband for pure and shear-enhanced compaction <span class="hlt">bands</span> from four sandstones from around the world. The value obtained previously for the Valley of Fire (Utah) site assumed compactional offsets only across the <span class="hlt">bands</span>; shearing offsets along these and shear-enhanced compaction <span class="hlt">bands</span> (SECBs) from the Buckskin Gulch (Utah) and the recently reported Boncavaï quarry near Mornas (France) are consistent with trigonometrically obtained estimates calculated from <span class="hlt">band</span> thickness and angle to the maximum compressive principal stress. Compactional offsets were calculated from porosity reductions from host rock to <span class="hlt">band</span>. Cataclastic deformation <span class="hlt">bands</span> from the Quartier de l'Etang quarry near Orange (France) were also analyzed for comparison with <span class="hlt">bands</span> having smaller ratios of shear/compaction. Normal and shear stresses resolved across the <span class="hlt">bands</span> at the time of their formation were estimated from stratigraphic overburden and friction coefficients for porous sandstones measured in the laboratory. Assuming that the SECBs may be characterized by small-scale yielding, so that Jband is equivalent to the strain <span class="hlt">energy</span> release rate G, the values of Jband can be compared to the previous values. SECBs having strike-slip offsets from Valley of Fire have Jband = 11.1 kJ/m2, consistent with the previously reported range of GIc = 10-60 kJ/m2 calculated by using the J-integral approach by Rudnicki and Sternlof [2005]. Pure compaction <span class="hlt">bands</span> (PCBs) from the same site have Jband = 5.5 kJ/m2, implying that less work is required to propagate PCBs than SECBs. The value of Jband for the Buckskin Gulch site, 60.5 kJ/m2, is consistent with the lower range of values for strain <span class="hlt">energy</span> release rate obtained previously, GIc = 55-120 kJ/m2. <span class="hlt">Band</span> propagation <span class="hlt">energy</span> for SECBs from the Boncavaï quarry site, Jband = 16.4 kJ/m2, is comparable to that for similar structures from the Valley of Fire site. Cataclastic deformation <span class="hlt">bands</span> at the Orange quarry</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5091263','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5091263"><span>Coherent structures in the <span class="hlt">ground</span> <span class="hlt">state</span> of the quantum Frenkel-Kontorova model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Berman, G.P.; Bulgakov, E.N. Kirensky Institute of Physics, Research Educational Center for Nonlinear Processes at Krasnoyarsk Technical University, Theoretical Department at Krasnoyarsk State University, 660036, Krasnoyarsk ); Campbell, D.K. )</p> <p>1994-03-15</p> <p>We study the quantum <span class="hlt">ground</span> <span class="hlt">state</span> of the Frenkel-Kontorova model in the strongly nonlinear'' regime in which in the corresponding classical limit the coordinates of the atoms are distributed on Cantori.'' We identify (many) quasidegenerate configurations that contribute to the quantum <span class="hlt">ground</span> <span class="hlt">state</span>. When the characteristic quantum and classical <span class="hlt">energy</span> scales are roughly equal (the intermediate'' quantum regime), we find, consistent with earlier numerical studies, that the standard map'' determining the coordinates in the classical <span class="hlt">ground</span> <span class="hlt">state</span> is renormalized to an effective sawtooth'' map, which determines the expectation values of the coordinates in the quantum <span class="hlt">ground</span> <span class="hlt">state</span>. We also discuss the dynamics of the model and estimate the characteristic time for various quantum tunneling effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ChPhB..24i0301M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ChPhB..24i0301M"><span><span class="hlt">Ground-state</span> information geometry and quantum criticality in an inhomogeneous spin model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Yu-Quan</p> <p>2015-09-01</p> <p>We investigate the <span class="hlt">ground-state</span> Riemannian metric and the cyclic quantum distance of an inhomogeneous quantum spin-1/2 chain in a transverse field. This model can be diagonalized by using a general canonical transformation to the fermionic Hamiltonian mapped from the spin system. The <span class="hlt">ground-state</span> Riemannian metric is derived exactly on a parameter manifold ring S1, which is introduced by performing a gauge transformation to the spin Hamiltonian through a twist operator. The cyclic <span class="hlt">ground-state</span> quantum distance and the second derivative of the <span class="hlt">ground-state</span> <span class="hlt">energy</span> are studied in different exchange coupling parameter regions. Particularly, we show that, in the case of exchange coupling parameter Ja = Jb, the quantum ferromagnetic phase can be characterized by an invariant quantum distance and this distance will decay to zero rapidly in the paramagnetic phase. Project supported by the National Natural Science Foundation of China (Grant Nos. 11404023 and 11347131).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JSemi..36a3001A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JSemi..36a3001A"><span>The calculation of <span class="hlt">band</span> gap <span class="hlt">energy</span> in zinc oxide films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arif, Ali; Belahssen, Okba; Gareh, Salim; Benramache, Said</p> <p>2015-01-01</p> <p>We investigated the optical properties of undoped zinc oxide thin films as the n-type semiconductor; the thin films were deposited at different precursor molarities by ultrasonic spray and spray pyrolysis techniques. The thin films were deposited at different substrate temperatures ranging between 200 and 500 °C. In this paper, we present a new approach to control the optical gap <span class="hlt">energy</span> of ZnO thin films by concentration of the ZnO solution and substrate temperatures from experimental data, which were published in international journals. The model proposed to calculate the <span class="hlt">band</span> gap <span class="hlt">energy</span> with the Urbach <span class="hlt">energy</span> was investigated. The relation between the experimental data and theoretical calculation suggests that the <span class="hlt">band</span> gap <span class="hlt">energies</span> are predominantly estimated by the Urbach <span class="hlt">energies</span>, film transparency, and concentration of the ZnO solution and substrate temperatures. The measurements by these proposal models are in qualitative agreements with the experimental data; the correlation coefficient values were varied in the range 0.96-0.99999, indicating high quality representation of data based on Equation (2), so that the relative errors of all calculation are smaller than 4%. Thus, one can suppose that the undoped ZnO thin films are chemically purer and have many fewer defects and less disorder owing to an almost complete chemical decomposition and contained higher optical <span class="hlt">band</span> gap <span class="hlt">energy</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.709a2009B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.709a2009B"><span>Experimental study of <span class="hlt">energy</span> harvesting in UHF <span class="hlt">band</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bernacki, Ł.; Gozdur, R.; Salamon, N.</p> <p>2016-04-01</p> <p>A huge progress of down-sizing technology together with trend of decreasing power consumption and, on the other hand, increasing efficiency of electronics give the opportunity to design and to implement the <span class="hlt">energy</span> harvesters as main power sources. This paper refers to the <span class="hlt">energy</span> that can be harvested from electromagnetic field in the unlicensed frequency <span class="hlt">bands</span>. The paper contains description of the most popular techniques and transducers that can be applied in <span class="hlt">energy</span> harvesting domain. The overview of current research and commercial solutions was performed for <span class="hlt">bands</span> in ultra-high frequency range, which are unlicensed and where transmission is not limited by administrative arrangements. During the experiments with Powercast’s receiver, the same <span class="hlt">bands</span> as sources of electromagnetic field were taken into account. This power source is used for conducting radio-communication process and excess <span class="hlt">energy</span> could be used for powering the extra electronic circuits. The paper presents elaborated prototype of <span class="hlt">energy</span> harvesting system and the measurements of power harvested in ultra-high frequency range. The evaluation of RF <span class="hlt">energy</span> harvesters for powering ultra-low power (ULP) electronic devices was performed based on survey and results of the experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AIPC.1072...27B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AIPC.1072...27B"><span>Universality of Mallmann correlations for nuclear <span class="hlt">band</span> structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bucurescu, D.; Zamfir, N. V.; Cǎta-Danil, G.; Ivaşcu, M.; Mǎrginean, N.</p> <p>2008-11-01</p> <p>It is shown that the Mallmann's <span class="hlt">energy</span> ratio correlations, first time proposed 50 years ago for the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">bands</span> of the even-even nuclei, are universal: all <span class="hlt">band</span> structures in collective nuclei obey the same systematics. Based on a second order anharmonic vibrator description, parameter-free recurrence relations are proposed for Mallmann-type <span class="hlt">energy</span> ratios, which can be used to extrapolate <span class="hlt">band</span> structures to higher spin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhRvC..78d4322B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhRvC..78d4322B"><span>Universality of Mallmann correlations for nuclear <span class="hlt">band</span> structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bucurescu, D.; Zamfir, N. V.; Căta-Danil, G.; Ivaşcu, M.; Mărginean, N.</p> <p>2008-10-01</p> <p>It is shown that the Mallmann's <span class="hlt">energy</span> ratio correlations, for the first time observed for the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">band</span> of the even-even nuclei, are universal: various <span class="hlt">band</span> structures in all collective nuclei obey the same systematics, and consequently the same spin dependence. Based on a second order anharmonic vibrator description, parameter-free recurrence relations between Mallmann-type <span class="hlt">energy</span> ratios are deduced, which can be used to extrapolate <span class="hlt">bands</span> to higher spin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/944340','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/944340"><span>Thermodynamic <span class="hlt">ground</span> <span class="hlt">states</span> of platinum metal nitrides</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Aberg, D; Sadigh, B; Crowhurst, J; Goncharov, A</p> <p>2007-10-09</p> <p>We have systematically studied the thermodynamic stabilities of various phases of the nitrides of the platinum metal elements using density functional theory. We show that for the nitrides of Rh, Pd, Ir and Pt two new crystal structures, in which the metal ions occupy simple tetragonal lattice sites, have lower formation enthalpies at ambient conditions than any previously proposed structures. The region of stability can extend up to 17 GPa for PtN{sub 2}. Furthermore, we show that according to calculations using the local density approximation, these new compounds are also thermodynamically stable at ambient pressure and thus may be the <span class="hlt">ground</span> <span class="hlt">state</span> phases for these materials. We further discuss the fact that the local density and generalized gradient approximations predict different values of the absolute formation enthalpies as well different relative stabilities between simple tetragonal and the pyrite or marcasite structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvC..95b4306D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvC..95b4306D"><span><span class="hlt">Ground-state</span> correlations within a nonperturbative approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>De Gregorio, G.; Herko, J.; Knapp, F.; Lo Iudice, N.; Veselý, P.</p> <p>2017-02-01</p> <p>The contribution of the two-phonon configurations to the <span class="hlt">ground</span> <span class="hlt">state</span> of 4He and 16O is evaluated nonperturbatively using a Hartree-Fock basis within an equation-of-motion phonon method using a nucleon-nucleon optimized chiral potential. Convergence properties of <span class="hlt">energies</span> and root-mean-square radii versus the harmonic oscillator frequency and space dimensions are investigated. The comparison with the second-order perturbation theory calculations shows that the higher-order terms have an appreciable repulsive effect and yield too-small binding <span class="hlt">energies</span> and nuclear radii. It is argued that four-phonon configurations, through their strong coupling to two phonons, may provide most of the attractive contribution necessary for filling the gap between theoretical and experimental quantities. Possible strategies for accomplishing such a challenging task are discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008APS..MARU27013G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008APS..MARU27013G"><span>Exact many-electron <span class="hlt">ground</span> <span class="hlt">states</span> on the diamond Hubbard chain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gulacsi, Zsolt; Kampf, Arno; Vollhardt, Dieter</p> <p>2008-03-01</p> <p>Exact <span class="hlt">ground</span> <span class="hlt">states</span> of interacting electrons on the diamond Hubbard chain in a magnetic field are constructed which exhibit a wide range of properties such as flat-<span class="hlt">band</span> ferromagnetism, correlation induced metallic, half-metallic, or insulating behavior [1]. The properties of these <span class="hlt">ground</span> <span class="hlt">states</span> can be tuned by changing the magnetic flux, local potentials, or electron density.The results show that the studied simple one-dimensional structure displays remarkably complex physical properties. The virtue of tuning different <span class="hlt">ground</span> <span class="hlt">states</span> through external parameters points to new possibilities for the design of electronic devices which can switch between insulating or conducting and nonmagnetic or (fully or partially spin polarized) ferromagnetic states, open new routes for the design of spin-valve devices and gate induced ferromagnetism. [1] Z. Gulacsi, A. Kampf, D. Vollhardt, Phys. Rev. Lett. 99, 026404(2007).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22390881','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22390881"><span>Antibonding hole <span class="hlt">ground</span> <span class="hlt">state</span> in InAs quantum dot molecules</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Planelles, Josep</p> <p>2015-01-22</p> <p>Using four-<span class="hlt">band</span> k⋅p Hamiltonians, we study how strain and position-dependent effective masses influence hole tunneling in vertically coupled InAs/GaAs quantum dots. Strain reduces the tunneling and hence the critical interdot distance required for the <span class="hlt">ground</span> <span class="hlt">state</span> to change from bonding to antibonding. Variable mass has the opposite effect and a rough compensation leaves little affected the critical bonding-to-antibonding <span class="hlt">ground</span> <span class="hlt">state</span> crossover. An alternative implementation of the magnetic field in the envelope function Hamiltonian is given which retrieves the experimental denial of possible after growth reversible magnetically induced bonding-to-antibonding <span class="hlt">ground</span> <span class="hlt">state</span> transition, predicted by the widely used Luttinger-Kohn Hamiltonian.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9743E..12U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9743E..12U"><span>Observation of mini-<span class="hlt">band</span> formation in the ground and high-<span class="hlt">energy</span> electronic states of super-lattice solar cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Usuki, Takanori; Matsuochi, Kouki; Nakamura, Tsubasa; Toprasertpong, Kasidit; Fukuyama, Atsuhiko; Sugiyama, Masakazu; Nakano, Yoshiaki; Ikari, Tetsuo</p> <p>2016-03-01</p> <p>Multiple Quantum wells (MQWs) have been studied as one promising material for high-efficiency nextgeneration solar cells. However, a portion of photo-excited carriers recombine in MQWs, resulting in the degradation of cell performance. Super-lattice (SL) structures, where quantum states in neighboring quantum wells strongly couple with each other, have been proposed for the carrier collection improvement via the tunneling transport through mini-<span class="hlt">bands</span>. Therefore, it is important to characterize mini-<span class="hlt">band</span> formation in various types of SL structures. We examined p-i-n GaAs-based solar cells whose i layers contain 20 stacks of InGaAs/GaAsP MQW structures with 2.1-nm GaAsP barriers (thin-barrier cell), with 2.1-nm barriers and 3-nm GaAs interlayers in between GaAsP barriers and InGaAs wells (stepbarrier cell), and with 7.8-nm barriers (thick-barrier cell). We investigated the optical absorption spectra of the SL solar cells using piezoelectric photo-thermal (PPT) spectroscopy. In the thick-barrier cell, one exciton peak was observed near the absorption edge of MQWs. On the other hand, we confirmed a split of the exciton peak for the thin-barrier SL, suggesting the formation of mini-<span class="hlt">band</span>. Moreover, in the step-barrier cell, the mini-<span class="hlt">band</span> at the <span class="hlt">ground</span> <span class="hlt">state</span> disappears since thick GaAs interlayers isolate each quantum-well <span class="hlt">ground</span> <span class="hlt">state</span> and, instead, the mini-<span class="hlt">band</span> formation of highenergy states could be observed. By estimating from the <span class="hlt">energy</span>-level calculation, this is attributed to the mini-<span class="hlt">band</span> formation of light-hole states. This can well explain the improvement of carrier collection efficiency (CCE) of the thinbarrier and the step-barrier cells compared with the thick-barrier cell.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10134320','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10134320"><span>Photonic <span class="hlt">Band</span> Gap resonators for high <span class="hlt">energy</span> accelerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schultz, S.; Smith, D.R.; Kroll, N. |</p> <p>1993-12-31</p> <p>We have proposed that a new type of microwave resonator, based on Photonic <span class="hlt">Band</span> Gap (PBG) structures, may be particularly useful for high <span class="hlt">energy</span> accelerators. We provide an explanation of the PBG concept and present data which illustrate some of the special properties associated with such structures. Further evaluation of the utility of PBG resonators requires laboratory testing of model structures at cryogenic temperatures, and at high fields. We provide a brief discussion of our test program, which is currently in progress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96c5310M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96c5310M"><span>Valence <span class="hlt">band</span> <span class="hlt">energy</span> spectrum of HgTe quantum wells with an inverted <span class="hlt">band</span> structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Minkov, G. M.; Aleshkin, V. Ya.; Rut, O. E.; Sherstobitov, A. A.; Germanenko, A. V.; Dvoretski, S. A.; Mikhailov, N. N.</p> <p>2017-07-01</p> <p>The <span class="hlt">energy</span> spectrum of the valence <span class="hlt">band</span> in HgTe /CdxHg1 -xTe quantum wells of a width (8 -20 ) nm has been studied experimentally by magnetotransport effects and theoretically in the framework of a four-<span class="hlt">band</span> k P method. Comparison of the Hall density with the density found from a period of the Shubnikov-de Haas (SdH) oscillations clearly shows that the degeneracy of states of the top of the valence <span class="hlt">band</span> is equal to 2 at the hole density p <5.5 ×1011cm-2 . Such degeneracy does not agree with the calculations of the spectrum performed within the framework of the four-<span class="hlt">band</span> k P method for symmetric quantum wells. These calculations show that the top of the valence <span class="hlt">band</span> consists of four spin-degenerate extremes located at k ≠0 (valleys) which gives the total degeneracy K =8 . It is shown that taking into account the "mixing of states" at the interfaces leads to the removal of the spin degeneracy that reduces the degeneracy to K =4 . Accounting for any additional asymmetry, for example, due to the difference in the mixing parameters at the interfaces, the different broadening of the boundaries of the well, etc., leads to reduction of the valleys degeneracy, making K =2 . It is noteworthy that for our case twofold degeneracy occurs due to degeneracy of two single-spin valleys. The hole effective mass (mh) determined from analysis of the temperature dependence of the amplitude of the SdH oscillations shows that mh is equal to (0.25 ±0.02 ) m0 and weakly increases with the hole density. Such a value of mh and its dependence on the hole density are in a good agreement with the calculated effective mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Prama..89...34G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Prama..89...34G"><span>A new perspective of ground <span class="hlt">band</span> <span class="hlt">energy</span> formulae</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gupta, J. B.</p> <p>2017-09-01</p> <p>A host of alternative <span class="hlt">energy</span> formulae for the ground <span class="hlt">bands</span> of even Z even N nuclei are available in the literature. The usual approach is to compare the relative numerical accuracy of the predictions of the level <span class="hlt">energies</span> by these formulae, for varying deformations of the nuclear core and for high spins. The soft rotor formula and variable moment of inertia model, the ab and pq formulae, the rotation vibration interaction and power index formulae are illustrated. Here, a new perspective is presented, with emphasis on the limitation of the region of their physical validity and on deriving useful meaning of their parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMMR31A1635K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMMR31A1635K"><span>On the Stable <span class="hlt">Ground</span> <span class="hlt">State</span> of Mackinawite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kwon, K.; Refson, K.; Sposito, G.</p> <p>2009-12-01</p> <p>Mackinawite is a layer type iron monosulfide (FeS) with stacked sheets of edge-sharing FeS4 tetrahedra. An important player in iron and sulfur cycles, mackinawite is one of the first-formed metastable iron sulfides in anoxic environments, transforming into greigite (Fe3S4) and pyrite (FeS2) minerals or elemental sulfur (S0) and iron (Fe0) depending on redox conditions. Mackinawite also affects the mobility and oxidation states of toxic metals such as As, Hg, and Se. The mineral, typically found as a nanoparticle, has been characterized experimentally. Its fundamental conducting and magnetic properties, however, are still controversial; e.g., whether mackinawite is metallic and whether it has magnetic order. Mackinawite is believed to be metallic and without magnetic ordering down at 4 K based on Mössbauer spectroscopy studies. We examined these two issues by applying plane-wave density functional theory (DFT) to FeS geometry optimization under different magnetic orderings. We found that antiferromagnetic ordering among the Fe atoms is the stable <span class="hlt">ground</span> <span class="hlt">state</span> of mackinawite. In this presentation, we shall discuss this result and how it relates to previous experimental work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983JMoSp.102..265J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983JMoSp.102..265J"><span>The <span class="hlt">ground</span> <span class="hlt">state</span> of molecular hydrogen</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jennings, D. E.; Brault, J. W.</p> <p>1983-12-01</p> <p>The v = 0-0 quadrupole spectrum of H2 has been recorded using a 0.005-cm-1 resolution Fourier transform spectrometer. The rotational lines S(1) through S(5) are observable in the spectra, in the region 587 to 1447 cm-1. The spectral position for S(0) was also obtained from its v = 1-0 <span class="hlt">ground-state</span> combination difference. The high accuracy of the H2 measurements has permitted a determination of four rotational constants. These are (in cm-1) B0 = 59.33455(6); D0 = 0.045682(4); H0 = 4.854(12) × 10-5 L0 = -5.41(12) × 10-8. The hydrogen line positions will facilitate studies of structure and dynamics in astrophysical objects exhibiting infrared H2 spectra. The absolute accuracy of frequency calibration over wide spectral ranges was verified using 10-μm CO2 and 3.39-μm CH4 laser frequencies. Standard frequencies for 5-μm CO were found to be high by 12 MHz (3.9 × 10-4 cm-1).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26785086','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26785086"><span>Stabilities and defect-mediated lithium-ion conduction in a <span class="hlt">ground</span> <span class="hlt">state</span> cubic Li3N structure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nguyen, Manh Cuong; Hoang, Khang; Wang, Cai-Zhuang; Ho, Kai-Ming</p> <p>2016-02-07</p> <p>A stable <span class="hlt">ground</span> <span class="hlt">state</span> structure with cubic symmetry of Li3N (c-Li3N) is found by an ab initio initially symmetric random-generated crystal structure search method. Gibbs free <span class="hlt">energy</span>, calculated within quasi-harmonic approximation, shows that c-Li3N is the <span class="hlt">ground</span> <span class="hlt">state</span> structure for a wide range of temperatures. The c-Li3N structure has a negative thermal expansion coefficient at temperatures lower than room temperature, mainly due to two transverse acoustic phonon modes. This c-Li3N phase is a semiconductor with an indirect <span class="hlt">band</span> gap of 1.90 eV within hybrid density functional calculations. We also investigate the migration and energetics of native point defects in c-Li3N, including lithium and nitrogen vacancies, interstitials, and anti-site defects. Lithium interstitials are found to have a very low migration barrier (∼ 0.12 eV) and the lowest formation <span class="hlt">energy</span> among all possible defects. The ionic conduction in c-Li3N is thus expected to occur via an interstitial mechanism, in contrast to that in the well-known α-Li3N phase which occurs via a vacancy mechanism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1249339-stabilities-defect-mediated-lithium-ion-conduction-ground-state-cubic-li3-structure','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1249339-stabilities-defect-mediated-lithium-ion-conduction-ground-state-cubic-li3-structure"><span>Stabilities and defect-mediated lithium-ion conduction in a <span class="hlt">ground</span> <span class="hlt">state</span> cubic Li3 N structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Nguyen, Manh Cuong; Hoang, Khang; Wang, Cai-Zhuang; ...</p> <p>2016-01-07</p> <p>A stable <span class="hlt">ground</span> <span class="hlt">state</span> structure with cubic symmetry of Li3N (c-Li3N) is found by ab initio initially symmetric random-generated crystal structure search method. Gibbs free <span class="hlt">energy</span>, calculated within quasi-harmonic approximation, shows that c-Li3N is the <span class="hlt">ground</span> <span class="hlt">state</span> structure for a wide range of temperature. The c-Li3N structure has a negative thermal expansion coefficient at temperatures lower than room temperature, due mainly to two transverse acoustic phonon modes. This c-Li3N phase is a semiconductor with an indirect <span class="hlt">band</span> gap of 1.90 eV within hybrid density functional calculation. We also investigate the migration and energetics of native point defects in c-Li3N, includingmore » lithium and nitrogen vacancies, interstitials, and anti-site defects. Lithium interstitials are found to have a very low migration barrier (~0.12 eV) and the lowest formation <span class="hlt">energy</span> among all possible defects. Thus, the ionic conduction in c-Li3N is expected to occur via an interstitial mechanism, in contrast to that in the well-known α-Li3N phase which occurs via a vacancy mechanism.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880064007&hterms=Violets&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DViolets','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880064007&hterms=Violets&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DViolets"><span>Theoretical study of the dissociation <span class="hlt">energy</span> and the red and violet <span class="hlt">band</span> systems of CN</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.</p> <p>1988-01-01</p> <p>The dissociation <span class="hlt">energy</span> D0 is determined here for the CN <span class="hlt">ground-state</span> and radiative lifetimes for the A 2Pi and B 2Sigma(+) states. D0 is found to be 7.65 + or - 0.06 eV, corresponding to Delta Hf (CN) = 105.3 + or - 1.5 kcal/mole. These results are compared with current experimental estimates and with previous theoretical calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95b4205K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95b4205K"><span>Universal crossover from <span class="hlt">ground-state</span> to excited-state quantum criticality</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kang, Byungmin; Potter, Andrew C.; Vasseur, Romain</p> <p>2017-01-01</p> <p>We study the nonequilibrium properties of a nonergodic random quantum chain in which highly excited eigenstates exhibit critical properties usually associated with quantum critical <span class="hlt">ground</span> <span class="hlt">states</span>. The <span class="hlt">ground</span> <span class="hlt">state</span> and excited states of this system belong to different universality classes, characterized by infinite-randomness quantum critical behavior. Using strong-disorder renormalization group techniques, we show that the crossover between the zero and finite <span class="hlt">energy</span> density regimes is universal. We analytically derive a flow equation describing the unitary dynamics of this isolated system at finite <span class="hlt">energy</span> density from which we obtain universal scaling functions along the crossover.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatCo...814277Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatCo...814277Y"><span>Charge transfer to <span class="hlt">ground-state</span> ions produces free electrons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K.</p> <p>2017-01-01</p> <p>Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-<span class="hlt">energy</span> free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic <span class="hlt">ground</span> <span class="hlt">state</span>. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne-Kr mixed clusters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910030254&hterms=1575&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2526%25231575','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910030254&hterms=1575&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2526%25231575"><span><span class="hlt">Ground</span> <span class="hlt">states</span> of partially connected binary neural networks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baram, Yoram</p> <p>1990-01-01</p> <p>Neural networks defined by outer products of vectors over (-1, 0, 1) are considered. Patterns over (-1, 0, 1) define by their outer products partially connected neural networks consisting of internally strongly connected, externally weakly connected subnetworks. Subpatterns over (-1, 1) define subnetworks, and their combinations that agree in the common bits define permissible words. It is shown that the permissible words are locally stable states of the network, provided that each of the subnetworks stores mutually orthogonal subwords, or, at most, two subwords. It is also shown that when each of the subnetworks stores two mutually orthogonal binary subwords at most, the permissible words, defined as the combinations of the subwords (one corresponding to each subnetwork), that agree in their common bits are the unique <span class="hlt">ground</span> <span class="hlt">states</span> of the associated <span class="hlt">energy</span> function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJWC.13202013L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJWC.13202013L"><span>LABS problem and <span class="hlt">ground</span> <span class="hlt">state</span> spin glasses system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leukhin, A. N.; Bezrodnyi, V. I.; Kozlova, Yu. A.</p> <p>2016-12-01</p> <p>In our work we demonstrate the new results of an exhaustive search for optimal binary sequences with minimum peak sidelobe (MPS) up to length N=85. The design problem for law autocorrelation binary sequences (LABS) is a notoriously difficult computational problem which is numbered as the problem number 005 in CSPLib. In statistical physics LABS problem can be interrepted as the <span class="hlt">energy</span> of N iteracting Ising spins. This is a Bernasconi model. Due to this connection to physics we refer a binary sequence as one-dimensional spin lattice. At this assumption optimal binary sequences by merit factor (MF) criteria are the <span class="hlt">ground-state</span> spin system without disorder which exhibits a glassy regime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21546778','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21546778"><span>Calculation of electron scattering from the <span class="hlt">ground</span> <span class="hlt">state</span> of ytterbium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bostock, Christopher J.; Fursa, Dmitry V.; Bray, Igor</p> <p>2011-05-15</p> <p>We report on the application of the convergent close-coupling method, in both relativistic and nonrelativistic formulations, to electron scattering from ytterbium. Angle-differential and integrated cross sections are presented for elastic scattering and excitation of the states (6s6p){sup 3}P{sub 0,1,2}, (6s6p){sup 1}P{sub 1}{sup o}, (6s7p){sup 1}P{sub 1}{sup o}, and (6s5d){sup 1}D{sub 2}{sup e} for a range of incident electron <span class="hlt">energies</span>. We also present calculations of the total cross section, and angle-differential Stokes parameters for excitation of the (6s6p){sup 3}P{sub 1}{sup o} state from the <span class="hlt">ground</span> <span class="hlt">state</span>. A comparison is made with the relativistic distorted-wave method and experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5290264','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5290264"><span>Charge transfer to <span class="hlt">ground-state</span> ions produces free electrons</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K</p> <p>2017-01-01</p> <p>Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-<span class="hlt">energy</span> free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic <span class="hlt">ground</span> <span class="hlt">state</span>. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne–Kr mixed clusters. PMID:28134238</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24675725','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24675725"><span>The behavior of f-levels in hcp and bcc rare-earth elements in the <span class="hlt">ground</span> <span class="hlt">state</span> and XPS and BIS spectroscopy from density-functional theory.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jarlborg, T</p> <p>2014-04-16</p> <p>The electronic structures of rare-earth elements in the hexagonal close-packed structure and Europium in the body-centered cubic structure are calculated using density-functional theory (DFT). X-ray photoemission spectroscopy (XPS) and bremsstrahlung isochromatic spectroscopy (BIS) simulations are made within DFT by implying that the f-electrons are excited by a large photon <span class="hlt">energy</span>, either by removal from the occupied states in XPS or by addition to the unoccupied f-states in BIS. The results show sizable differences in the apparent position of the f-states compared to the f-<span class="hlt">band</span> <span class="hlt">energy</span> of the <span class="hlt">ground</span> <span class="hlt">states</span>. This result is fundamentally different from calculations assuming strong on-site correlation, since all the calculations are based on DFT. The spin-orbit coupling and multiplet splittings are not included, and the present simulation accounts for almost half of the difference between the f-level positions in the DFT <span class="hlt">ground</span> <span class="hlt">states</span> and the observed f-level positions. The electronic specific-heat at low T is compatible with the DFT <span class="hlt">ground</span> <span class="hlt">state</span>, where f-electrons often reside at the Fermi level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017CP....493..194Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CP....493..194Z"><span>Plasmon enhanced heterogeneous electron transfer with continuous <span class="hlt">band</span> <span class="hlt">energy</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Dandan; Niu, Lu; Wang, Luxia</p> <p>2017-08-01</p> <p>Photoinduced charge injection from a perylene dye molecule into the conduction <span class="hlt">band</span> of a TiO2 system decorated by a metal nanoparticles (MNP) is studied theoretically. Utilizing the density matrix theory the charge transfer dynamics is analyzed. The continuous behavior of the TiO2 conduction <span class="hlt">band</span> is accounted for by a Legendre polynomials expansion. The simulations consider optical excitation of the dye molecule coupled to the MNP and the subsequent electron injection into the TiO2 semiconductor. Due to the <span class="hlt">energy</span> transfer coupling between the molecule and the MNP optical excitation and subsequent charge injection into semiconductor is strongly enhanced. The respective enhancement factor can reach values larger than 103. Effects of pulse duration, coupling strength and energetic resonances are also analyzed. The whole approach offers an efficient way to increase charge injection in dye-sensitized solar cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22493679','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22493679"><span>Exact two-component relativistic <span class="hlt">energy</span> <span class="hlt">band</span> theory and application</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhao, Rundong; Zhang, Yong; Xiao, Yunlong; Liu, Wenjian</p> <p>2016-01-28</p> <p>An exact two-component (X2C) relativistic density functional theory in terms of atom-centered basis functions is proposed for relativistic calculations of <span class="hlt">band</span> structures and structural properties of periodic systems containing heavy elements. Due to finite radial extensions of the local basis functions, the periodic calculation is very much the same as a molecular calculation, except only for an Ewald summation for the Coulomb potential of fluctuating periodic monopoles. For comparison, the nonrelativistic and spin-free X2C counterparts are also implemented in parallel. As a first and pilot application, the <span class="hlt">band</span> gaps, lattice constants, cohesive <span class="hlt">energies</span>, and bulk moduli of AgX (X = Cl, Br, I) are calculated to compare with other theoretical results.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPCM...29v4004A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPCM...29v4004A"><span>Low <span class="hlt">energy</span> <span class="hlt">bands</span> and transport properties of chromium arsenide</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Autieri, Carmine; Cuono, Giuseppe; Forte, Filomena; Noce, Canio</p> <p>2017-06-01</p> <p>We apply a method that combines the tight-binding approximation and the Löwdin down-folding procedure to evaluate the electronic <span class="hlt">band</span> structure of the newly discovered pressure-induced superconductor CrAs. By integrating out all low-lying arsenic degrees of freedom, we derive an effective Hamiltonian model describing the Cr d <span class="hlt">bands</span> near the Fermi level. We calculate and make predictions for the <span class="hlt">energy</span> spectra, the Fermi surface, the density of states and transport and magnetic properties of this compound. Our results are consistent with local-density approximation calculations and they also show good agreement with available experimental data for resistivity and the Cr magnetic moment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22493114','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22493114"><span>Measurement of InAsSb bandgap <span class="hlt">energy</span> and InAs/InAsSb <span class="hlt">band</span> edge positions using spectroscopic ellipsometry and photoluminescence spectroscopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Webster, P. T.; Riordan, N. A.; Liu, S.; Zhang, Y.-H.; Johnson, S. R.; Steenbergen, E. H.</p> <p>2015-12-28</p> <p>The structural and optical properties of lattice-matched InAs{sub 0.911}Sb{sub 0.089} bulk layers and strain-balanced InAs/InAs{sub 1−x}Sb{sub x} (x ∼ 0.1–0.4) superlattices grown on (100)-oriented GaSb substrates by molecular beam epitaxy are examined using X-ray diffraction, spectroscopic ellipsometry, and temperature dependent photoluminescence spectroscopy. The photoluminescence and ellipsometry measurements determine the <span class="hlt">ground</span> <span class="hlt">state</span> bandgap <span class="hlt">energy</span> and the X-ray diffraction measurements determine the layer thickness and mole fraction of the structures studied. Detailed modeling of the X-ray diffraction data is employed to quantify unintentional incorporation of approximately 1% Sb into the InAs layers of the superlattices. A Kronig-Penney model of the superlattice miniband structure is used to analyze the valence <span class="hlt">band</span> offset between InAs and InAsSb, and hence the InAsSb <span class="hlt">band</span> edge positions at each mole fraction. The resulting composition dependence of the bandgap <span class="hlt">energy</span> and <span class="hlt">band</span> edge positions of InAsSb are described using the bandgap bowing model; the respective low and room temperature bowing parameters for bulk InAsSb are 938 and 750 meV for the bandgap, 558 and 383 meV for the conduction <span class="hlt">band</span>, and −380 and −367 meV for the valence <span class="hlt">band</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21250649','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21250649"><span>Is the <span class="hlt">ground</span> <span class="hlt">state</span> of Yang-Mills theory Coulombic?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Heinzl, T.; Ilderton, A.; Langfeld, K.; Lavelle, M.; McMullan, D.; Lutz, W.</p> <p>2008-08-01</p> <p>We study trial states modelling the heavy quark-antiquark <span class="hlt">ground</span> <span class="hlt">state</span> in SU(2) Yang-Mills theory. A state describing the flux tube between quarks as a thin string of glue is found to be a poor description of the continuum <span class="hlt">ground</span> <span class="hlt">state</span>; the infinitesimal thickness of the string leads to UV artifacts which suppress the overlap with the <span class="hlt">ground</span> <span class="hlt">state</span>. Contrastingly, a state which surrounds the quarks with non-Abelian Coulomb fields is found to have a good overlap with the <span class="hlt">ground</span> <span class="hlt">state</span> for all charge separations. In fact, the overlap increases as the lattice regulator is removed. This opens up the possibility that the Coulomb state is the true <span class="hlt">ground</span> <span class="hlt">state</span> in the continuum limit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21583317','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21583317"><span>On the <span class="hlt">ground</span> <span class="hlt">state</span> of Yang-Mills theory</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bakry, Ahmed S.; Leinweber, Derek B.; Williams, Anthony G.</p> <p>2011-08-15</p> <p>Highlights: > The <span class="hlt">ground</span> <span class="hlt">state</span> overlap for sets of meson potential trial states is measured. > Non-uniform gluonic distributions are probed via Wilson loop operator. > The locally UV-regulated flux-tube operators can optimize the <span class="hlt">ground</span> <span class="hlt">state</span> overlap. - Abstract: We investigate the overlap of the <span class="hlt">ground</span> <span class="hlt">state</span> meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the <span class="hlt">ground</span> <span class="hlt">state</span> and display interesting features in the <span class="hlt">ground</span> <span class="hlt">state</span> overlap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22382119','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22382119"><span>A projection gradient method for computing <span class="hlt">ground</span> <span class="hlt">state</span> of spin-2 Bose–Einstein condensates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, Hanquan</p> <p>2014-10-01</p> <p>In this paper, a projection gradient method is presented for computing <span class="hlt">ground</span> <span class="hlt">state</span> of spin-2 Bose–Einstein condensates (BEC). We first propose the general projection gradient method for solving <span class="hlt">energy</span> functional minimization problem under multiple constraints, in which the <span class="hlt">energy</span> functional takes real functions as independent variables. We next extend the method to solve a similar problem, where the <span class="hlt">energy</span> functional now takes complex functions as independent variables. We finally employ the method into finding the <span class="hlt">ground</span> <span class="hlt">state</span> of spin-2 BEC. The key of our method is: by constructing continuous gradient flows (CGFs), the <span class="hlt">ground</span> <span class="hlt">state</span> of spin-2 BEC can be computed as the steady state solution of such CGFs. We discretized the CGFs by a conservative finite difference method along with a proper way to deal with the nonlinear terms. We show that the numerical discretization is normalization and magnetization conservative and <span class="hlt">energy</span> diminishing. Numerical results of the <span class="hlt">ground</span> <span class="hlt">state</span> and their <span class="hlt">energy</span> of spin-2 BEC are reported to demonstrate the effectiveness of the numerical method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvL.118g0502M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvL.118g0502M"><span>Exponentially Biased <span class="hlt">Ground-State</span> Sampling of Quantum Annealing Machines with Transverse-Field Driving Hamiltonians</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mandrà, Salvatore; Zhu, Zheng; Katzgraber, Helmut G.</p> <p>2017-02-01</p> <p>We study the performance of the D-Wave 2X quantum annealing machine on systems with well-controlled <span class="hlt">ground-state</span> degeneracy. While obtaining the <span class="hlt">ground</span> <span class="hlt">state</span> of a spin-glass benchmark instance represents a difficult task, the gold standard for any optimization algorithm or machine is to sample all solutions that minimize the Hamiltonian with more or less equal probability. Our results show that while naive transverse-field quantum annealing on the D-Wave 2X device can find the <span class="hlt">ground-state</span> <span class="hlt">energy</span> of the problems, it is not well suited in identifying all degenerate <span class="hlt">ground-state</span> configurations associated with a particular instance. Even worse, some states are exponentially suppressed, in agreement with previous studies on toy model problems [New J. Phys. 11, 073021 (2009), 10.1088/1367-2630/11/7/073021]. These results suggest that more complex driving Hamiltonians are needed in future quantum annealing machines to ensure a fair sampling of the <span class="hlt">ground-state</span> manifold.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvB..92k5137K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvB..92k5137K"><span>Exact <span class="hlt">ground</span> <span class="hlt">states</span> and topological order in interacting Kitaev/Majorana chains</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Katsura, Hosho; Schuricht, Dirk; Takahashi, Masahiro</p> <p>2015-09-01</p> <p>We study a system of interacting spinless fermions in one dimension that, in the absence of interactions, reduces to the Kitaev chain [Kitaev, Phys. Usp. 44, 131 (2001), 10.1070/1063-7869/44/10S/S29]. In the noninteracting case, a signal of topological order appears as zero-<span class="hlt">energy</span> modes localized near the edges. We show that the exact <span class="hlt">ground</span> <span class="hlt">states</span> can be obtained analytically even in the presence of nearest-neighbor repulsive interactions when the on-site (chemical) potential is tuned to a particular function of the other parameters. As with the noninteracting case, the obtained <span class="hlt">ground</span> <span class="hlt">states</span> are twofold degenerate and differ in fermionic parity. We prove the uniqueness of the obtained <span class="hlt">ground</span> <span class="hlt">states</span> and show that they can be continuously deformed to the <span class="hlt">ground</span> <span class="hlt">states</span> of the noninteracting Kitaev chain without gap closing. We also demonstrate explicitly that there exists a set of operators each of which maps one of the <span class="hlt">ground</span> <span class="hlt">states</span> to the other with opposite fermionic parity. These operators can be thought of as an interacting generalization of Majorana edge zero modes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28256849','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28256849"><span>Exponentially Biased <span class="hlt">Ground-State</span> Sampling of Quantum Annealing Machines with Transverse-Field Driving Hamiltonians.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mandrà, Salvatore; Zhu, Zheng; Katzgraber, Helmut G</p> <p>2017-02-17</p> <p>We study the performance of the D-Wave 2X quantum annealing machine on systems with well-controlled <span class="hlt">ground-state</span> degeneracy. While obtaining the <span class="hlt">ground</span> <span class="hlt">state</span> of a spin-glass benchmark instance represents a difficult task, the gold standard for any optimization algorithm or machine is to sample all solutions that minimize the Hamiltonian with more or less equal probability. Our results show that while naive transverse-field quantum annealing on the D-Wave 2X device can find the <span class="hlt">ground-state</span> <span class="hlt">energy</span> of the problems, it is not well suited in identifying all degenerate <span class="hlt">ground-state</span> configurations associated with a particular instance. Even worse, some states are exponentially suppressed, in agreement with previous studies on toy model problems [New J. Phys. 11, 073021 (2009)NJOPFM1367-263010.1088/1367-2630/11/7/073021]. These results suggest that more complex driving Hamiltonians are needed in future quantum annealing machines to ensure a fair sampling of the <span class="hlt">ground-state</span> manifold.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJMPA..3141014G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJMPA..3141014G"><span><span class="hlt">Ground</span> <span class="hlt">state</span> of the universe in quantum cosmology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gorobey, Natalia; Lukyanenko, Alexander</p> <p>2016-01-01</p> <p>We find a physical state of a closed universe with the minimal excitation of the universe expansion <span class="hlt">energy</span> in quantum gravity. It is an analog of the vacuum state of the ordinary quantum field theory in the Minkowsky space, but in our approach an <span class="hlt">energy</span> of space of a closed universe together with the <span class="hlt">energy</span> of its matter content are minimized. This <span class="hlt">ground</span> <span class="hlt">state</span> is chosen among an enlarged set of physical states, compared with the ordinary covariant quantum gravity. In our approach, physical states are determined by weak constraints: quantum mechanical averages of gravitational constraint operators equal zero. As a result, they appear to be non-static in such a modification of quantum gravity. Quantum dynamics of the universe is described by Schrödinger equation with a cosmic time determined by weak gravitational constraints. In order to obtain the observed megascopic universe with the inflation stage just after its quantum beginning, a lot of the <span class="hlt">energy</span> in the form of the inflaton scalar field condensate is prescribed to the initial state. Parameters of the initial state for a homogeneous model of the universe are calculated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26567645','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26567645"><span><span class="hlt">Ground-state</span> densities from the Rayleigh-Ritz variation principle and from density-functional theory.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kvaal, Simen; Helgaker, Trygve</p> <p>2015-11-14</p> <p>The relationship between the densities of <span class="hlt">ground-state</span> wave functions (i.e., the minimizers of the Rayleigh-Ritz variation principle) and the <span class="hlt">ground-state</span> densities in density-functional theory (i.e., the minimizers of the Hohenberg-Kohn variation principle) is studied within the framework of convex conjugation, in a generic setting covering molecular systems, solid-state systems, and more. Having introduced admissible density functionals as functionals that produce the exact <span class="hlt">ground-state</span> <span class="hlt">energy</span> for a given external potential by minimizing over densities in the Hohenberg-Kohn variation principle, necessary and sufficient conditions on such functionals are established to ensure that the Rayleigh-Ritz <span class="hlt">ground-state</span> densities and the Hohenberg-Kohn <span class="hlt">ground-state</span> densities are identical. We apply the results to molecular systems in the Born-Oppenheimer approximation. For any given potential v ∈ L(3/2)(ℝ(3)) + L(∞)(ℝ(3)), we establish a one-to-one correspondence between the mixed <span class="hlt">ground-state</span> densities of the Rayleigh-Ritz variation principle and the mixed <span class="hlt">ground-state</span> densities of the Hohenberg-Kohn variation principle when the Lieb density-matrix constrained-search universal density functional is taken as the admissible functional. A similar one-to-one correspondence is established between the pure <span class="hlt">ground-state</span> densities of the Rayleigh-Ritz variation principle and the pure <span class="hlt">ground-state</span> densities obtained using the Hohenberg-Kohn variation principle with the Levy-Lieb pure-state constrained-search functional. In other words, all physical <span class="hlt">ground-state</span> densities (pure or mixed) are recovered with these functionals and no false densities (i.e., minimizing densities that are not physical) exist. The importance of topology (i.e., choice of Banach space of densities and potentials) is emphasized and illustrated. The relevance of these results for current-density-functional theory is examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJC...76...64B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJC...76...64B"><span>Traces of Lorentz symmetry breaking in a hydrogen atom at <span class="hlt">ground</span> <span class="hlt">state</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Borges, L. H. C.; Barone, F. A.</p> <p>2016-02-01</p> <p>Some traces of a specific Lorentz symmetry breaking scenario in the <span class="hlt">ground</span> <span class="hlt">state</span> of the hydrogen atom are investigated. We use standard Rayleigh-Schrödinger perturbation theory in order to obtain the corrections to the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span> and the wave function. It is shown that an induced four-pole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in Borges et al. (Eur Phys J C 74:2937, 2014), where the Lorentz symmetry is broken in the electromagnetic sector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015FoPh...45.1190N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015FoPh...45.1190N"><span>Simulation of the Hydrogen <span class="hlt">Ground</span> <span class="hlt">State</span> in Stochastic Electrodynamics-2: Inclusion of Relativistic Corrections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nieuwenhuizen, Theodorus M.; Liska, Matthew T. P.</p> <p>2015-10-01</p> <p>In a recent paper the authors studied numerically the hydrogen <span class="hlt">ground</span> <span class="hlt">state</span> in stochastic electrodynamics (SED) within the the non-relativistic approximation. In quantum theory the leading non-relativistic corrections to the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span> dominate the Lamb shift related to the photon cloud that should cause the quantum-like behaviour of SED. The present work takes these corrections into account in the numerical modelling. It is found that they have little effect; the self-ionisation that occurs without them remains present. It is speculated that the point-charge approximation for the electron is the cause of the failure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19392338','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19392338"><span>Preparing <span class="hlt">ground</span> <span class="hlt">States</span> of quantum many-body systems on a quantum computer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Poulin, David; Wocjan, Pawel</p> <p>2009-04-03</p> <p>Preparing the <span class="hlt">ground</span> <span class="hlt">state</span> of a system of interacting classical particles is an NP-hard problem. Thus, there is in general no better algorithm to solve this problem than exhaustively going through all N configurations of the system to determine the one with lowest <span class="hlt">energy</span>, requiring a running time proportional to N. A quantum computer, if it could be built, could solve this problem in time sqrt[N]. Here, we present a powerful extension of this result to the case of interacting quantum particles, demonstrating that a quantum computer can prepare the <span class="hlt">ground</span> <span class="hlt">state</span> of a quantum system as efficiently as it does for classical systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18517964','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18517964"><span>First-principles prediction of a <span class="hlt">ground</span> <span class="hlt">state</span> crystal structure of magnesium borohydride.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ozolins, V; Majzoub, E H; Wolverton, C</p> <p>2008-04-04</p> <p>Mg(BH(4))(2) contains a large amount of hydrogen by weight and by volume, but its promise as a candidate for hydrogen storage is dependent on the currently unknown thermodynamics of H2 release. Using first-principles density-functional theory calculations and a newly developed prototype electrostatic <span class="hlt">ground</span> <span class="hlt">state</span> search strategy, we predict a new T=0 K <span class="hlt">ground</span> <span class="hlt">state</span> of Mg(BH(4))(2) with I4[over ]m2 symmetry, which is 5 kJ/mol lower in <span class="hlt">energy</span> than the recently proposed P6(1) structure. The calculated thermodynamics of H(2) release are within the range required for reversible storage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21180325','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21180325"><span>Preparing <span class="hlt">Ground</span> <span class="hlt">States</span> of Quantum Many-Body Systems on a Quantum Computer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Poulin, David; Wocjan, Pawel</p> <p>2009-04-03</p> <p>Preparing the <span class="hlt">ground</span> <span class="hlt">state</span> of a system of interacting classical particles is an NP-hard problem. Thus, there is in general no better algorithm to solve this problem than exhaustively going through all N configurations of the system to determine the one with lowest <span class="hlt">energy</span>, requiring a running time proportional to N. A quantum computer, if it could be built, could solve this problem in time {radical}(N). Here, we present a powerful extension of this result to the case of interacting quantum particles, demonstrating that a quantum computer can prepare the <span class="hlt">ground</span> <span class="hlt">state</span> of a quantum system as efficiently as it does for classical systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16090737','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16090737"><span><span class="hlt">Ground</span> <span class="hlt">state</span> proton radioactivity from 121Pr: when was this exotic nuclear decay mode first discovered?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Robinson, A P; Woods, P J; Seweryniak, D; Davids, C N; Carpenter, M P; Hecht, A A; Peterson, D; Sinha, S; Walters, W B; Zhu, S</p> <p>2005-07-15</p> <p><span class="hlt">Ground-state</span> proton radioactivity has been identified from 121Pr. A transition with a proton <span class="hlt">energy</span> of E(p)=882(10) keV [Q(p)=900(10) keV] and half-life t(1/2)=10(+6)(-3) ms has been observed and is assigned to the decay of a highly prolate deformed 3/2(+) or 3/2(-) Nilsson state. The present result is found to be incompatible with a previously reported observation of <span class="hlt">ground-state</span> proton radioactivity from 121Pr, which would have represented the discovery of this phenomenon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5890157','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5890157"><span><span class="hlt">Ground-state</span> properties of third-row elements with nonlocal density functionals</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bagno, P.; Jepsen, O.; Gunnarsson, O.</p> <p>1989-07-15</p> <p>The cohesive <span class="hlt">energy</span>, the lattice parameter, and the bulk modulus of third-row elements are calculated using the Langreth-Mehl-Hu (LMH), the Perdew-Wang (PW), and the gradient expansion functionals. The PW functional is found to give somewhat better results than the LMH functional and both are found to typically remove half the errors in the local-spin-density (LSD) approximation, while the gradient expansion gives worse results than the local-density approximation. For Fe both the LMH and PW functionals correctly predict a ferromagnetic bcc <span class="hlt">ground</span> <span class="hlt">state</span>, while the LSD approximation and the gradient expansion predict a nonmagnetic fcc <span class="hlt">ground</span> <span class="hlt">state</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22560246','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22560246"><span>Trajectory approach to the Schrödinger–Langevin equation with linear dissipation for <span class="hlt">ground</span> <span class="hlt">states</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chou, Chia-Chun</p> <p>2015-11-15</p> <p>The Schrödinger–Langevin equation with linear dissipation is integrated by propagating an ensemble of Bohmian trajectories for the <span class="hlt">ground</span> <span class="hlt">state</span> of quantum systems. Substituting the wave function expressed in terms of the complex action into the Schrödinger–Langevin equation yields the complex quantum Hamilton–Jacobi equation with linear dissipation. We transform this equation into the arbitrary Lagrangian–Eulerian version with the grid velocity matching the flow velocity of the probability fluid. The resulting equation is simultaneously integrated with the trajectory guidance equation. Then, the computational method is applied to the harmonic oscillator, the double well potential, and the ground vibrational state of methyl iodide. The excellent agreement between the computational and the exact results for the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energies</span> and wave functions shows that this study provides a synthetic trajectory approach to the <span class="hlt">ground</span> <span class="hlt">state</span> of quantum systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ArRMA.222.1581T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ArRMA.222.1581T"><span>Uniqueness of Positive <span class="hlt">Ground</span> <span class="hlt">State</span> Solutions of the Logarithmic Schrödinger Equation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Troy, William C.</p> <p>2016-12-01</p> <p>We prove the uniqueness of positive <span class="hlt">ground</span> <span class="hlt">state</span> solutions of the problem { {{d2u}/{dr2}} + {{n-1}/{r}}{du/dr}} + u ln(|u|) = 0}, {u(r) > 0 forall r ≥ 0}, and {(u(r),u'(r)) to (0, 0)} as {r to ∞}. This equation is derived from the logarithmic Schrödinger equation {iψt = {Δ} ψ + u ln (|u|2)}, and also from the classical equation {{{partial u}/{partial t}} = {Δ} u +u (|u|^{p-1}) -u}. For each {n ≥ 1}, a positive <span class="hlt">ground</span> <span class="hlt">state</span> solution is { u0(r) = exp (-{r^2/4} + {n/2}), 0 ≤ r < ∞}. We combine {u0(r)} with <span class="hlt">energy</span> estimates and associated Ricatti equation estimates to prove that, for each {n in [1, 9 ]}, {u0(r)} is the only positive <span class="hlt">ground</span> <span class="hlt">state</span>. We also investigate the stability of {u0(r)}. Several open problems are stated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JDE...262..486F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JDE...262..486F"><span>Existence of <span class="hlt">ground</span> <span class="hlt">state</span> solutions to Dirac equations with vanishing potentials at infinity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Figueiredo, Giovany M.; Pimenta, Marcos T. O.</p> <p>2017-01-01</p> <p>In this work we study the existence of <span class="hlt">ground-state</span> solutions of Dirac equations with potentials which are allowed to vanish at infinity. The approach is based on minimization of the <span class="hlt">energy</span> functional over a generalized Nehari set. Some conditions on the potentials are given in order to overcome the lack of compactness.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21541280','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21541280"><span>Hylleraas-configuration-interaction study of the {sup 1}S <span class="hlt">ground</span> <span class="hlt">state</span> of neutral beryllium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sims, James S.; Hagstrom, Stanley A.</p> <p>2011-03-15</p> <p>Hylleraas-configuration-interaction (Hy-CI) method variational calculations are reported for the {sup 1}S <span class="hlt">ground</span> <span class="hlt">state</span> of neutral beryllium. The best nonrelativistic <span class="hlt">energy</span> obtained was -14.667 356 4 hartree, which is estimated to be accurate to a tenth of a microhartree.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006APS..MARD45011P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006APS..MARD45011P"><span><span class="hlt">Ground-state</span> valency and spin configuration of the nickelates.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petit, Leon; Stocks, George M.; Egami, Takeshi; Szotek, Zdzislawa; Temmerman, Walter M.</p> <p>2006-03-01</p> <p>The ab initio self-interaction-corrected local-spin-density approximation is used to study the electronic structure of both stoichiometric and non-stoichiometric nickelates. From total <span class="hlt">energy</span> considerations it emerges that, in their <span class="hlt">ground-state</span>, both LiNiO2, and NaNiO2 are insulators, with the Ni ion in the Ni^3+ low spin state (t2g^6eg^1) configuration. We find that the substitution of Li/Na atoms by divalent impurities, drives an equivalent number of Ni ions in the NiO2 layers from the JT-active trivalent low-spin state to the divalent JT-inactive state. We propose that an experimental study on MgxNa1-xNiO2 might clarify the role of Ni^2+ impurities with respect to the vanishing of long range orbital ordering in Li1-xNi1+xO2. (Work sponsored by the Laboratory Directed Research and Development Program (LDRD) program of ORNL (LP, GMS, TE), and by the DOE-OS through the Offices of Basic <span class="hlt">Energy</span> Sciences (BES), Division of Materials Sciences and Engineering (LP, GMS, TE). Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the Department of <span class="hlt">Energy</span> under Contract No. DE-AC05-00OR22725.)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhLA..374.2510K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhLA..374.2510K"><span>Topology of the space of periodic <span class="hlt">ground</span> <span class="hlt">states</span> in the antiferromagnetic Ising and Potts models in selected spatial structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krawczyk, Małgorzata J.</p> <p>2010-05-01</p> <p>Topology of the space of periodic <span class="hlt">ground</span> <span class="hlt">states</span> in the antiferromagnetic Ising and Potts (3-state) models is analysed in selected spatial structures. The states are treated as graph nodes, connected by one-spin-flip transitions. The spatial structures are the triangular lattice, the Archimedean ( 3,12) lattice and the cubic Laves C15 lattice with the periodic boundary conditions. In most cases the <span class="hlt">ground</span> <span class="hlt">states</span> are isolated nodes, but for selected systems we obtain connected graphs. The latter means that the magnetisation can vary in time with zero <span class="hlt">energy</span> cost. The <span class="hlt">ground</span> <span class="hlt">states</span> are classified according to their degree and type of neighbours.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28458746','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28458746"><span>Identification of <span class="hlt">ground-state</span> spin ordering in antiferromagnetic transition metal oxides using the Ising model and a genetic algorithm.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Kyuhyun; Youn, Yong; Han, Seungwu</p> <p>2017-01-01</p> <p>We identify <span class="hlt">ground-state</span> collinear spin ordering in various antiferromagnetic transition metal oxides by constructing the Ising model from first-principles results and applying a genetic algorithm to find its minimum <span class="hlt">energy</span> state. The present method can correctly reproduce the <span class="hlt">ground</span> <span class="hlt">state</span> of well-known antiferromagnetic oxides such as NiO, Fe2O3, Cr2O3 and MnO2. Furthermore, we identify the <span class="hlt">ground-state</span> spin ordering in more complicated materials such as Mn3O4 and CoCr2O4.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JNuM..479...59L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JNuM..479...59L"><span><span class="hlt">Ground</span> <span class="hlt">state</span> of the U2Mo compound: Physical properties of the Ω-phase</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Losada, E. L.; Garcés, J. E.</p> <p>2016-10-01</p> <p>Using ab initio calculations, unexpected structural instability was recently found in the <span class="hlt">ground</span> <span class="hlt">state</span> of the U2 Mo compound. Instead of the unstable I4/mmm and the Pmmn structures, in this work the P6/mmm (#191) space group, usually called Ω-phase, is proposed as the fundamental state. Total <span class="hlt">energy</span> calculations using Wien2k code slightly favoured the last structure. Electronic and elastic properties are studied in this work in order to characterize the physical properties of this new phase. The stability of the Ω-phase is studied by means of its elastic constants calculation and phonon dispersion spectrum. Analysis of isotropic indices shows that the new phase is a ductile material with a minimal degree of anisotropy, suggesting that U2 Mo in the P6/mmm structure is an elastic isotropic material. Analysis of charge density, density of electronic states (DOS) and the character of the <span class="hlt">bands</span> revealed a high level of hybridization between d-molybdenum electronic states and d- and f-uranium ones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyA..444..397S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyA..444..397S"><span>Analysis of <span class="hlt">ground</span> <span class="hlt">state</span> in random bipartite matching</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Gui-Yuan; Kong, Yi-Xiu; Liao, Hao; Zhang, Yi-Cheng</p> <p>2016-02-01</p> <p>Bipartite matching problems emerge in many human social phenomena. In this paper, we study the <span class="hlt">ground</span> <span class="hlt">state</span> of the Gale-Shapley model, which is the most popular bipartite matching model. We apply the Kuhn-Munkres algorithm to compute the numerical <span class="hlt">ground</span> <span class="hlt">state</span> of the model. For the first time, we obtain the number of blocking pairs which is a measure of the system instability. We also show that the number of blocking pairs formed by each person follows a geometric distribution. Furthermore, we study how the connectivity in the bipartite matching problems influences the instability of the <span class="hlt">ground</span> <span class="hlt">state</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhLB..767...58L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhLB..767...58L"><span>Intruder configurations in the <span class="hlt">ground</span> <span class="hlt">state</span> of 30Ne</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, H. N.; Lee, J.; Doornenbal, P.; Scheit, H.; Takeuchi, S.; Aoi, N.; Li, K. A.; Matsushita, M.; Steppenbeck, D.; Wang, H.; Baba, H.; Ideguchi, E.; Kobayashi, N.; Kondo, Y.; Lee, G.; Michimasa, S.; Motobayashi, T.; Poves, A.; Sakurai, H.; Takechi, M.; Togano, Y.; Tostevin, J. A.; Utsuno, Y.</p> <p>2017-04-01</p> <p>We report on the first detailed study of intruder configurations in the <span class="hlt">ground</span> <span class="hlt">state</span> of 30Ne by means of the 12C(30Ne, 29Ne+γ)X one-neutron knockout reaction at 228 MeV/nucleon. Using a combined analysis of individual parallel momentum distributions and partial cross sections we find: (a) comparable p- and d-wave removal strength to 29Ne final states with excitation <span class="hlt">energies</span> below 200 keV, and (b) significant p-wave removal strength to the 620 keV state of 29Ne, and (c) no evidence for f-wave intruder strength leading to bound 29Ne final states. The SDPF-U-MIX shell model calculation in the sd- pf model space provides a better overall agreement with the measured <span class="hlt">energy</span> levels of 29Ne and the fp-intruder amplitudes in 30Ne than the SDPF-M prediction, suggesting that the refinement of the sd- pf cross shell interaction and extension of the model space to include the 2p1/2 and 1f5/2 levels are important for understanding the island of inversion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvC..89d4610W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvC..89d4610W"><span><span class="hlt">Ground-state</span> properties of neutron-rich Mg isotopes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watanabe, S.; Minomo, K.; Shimada, M.; Tagami, S.; Kimura, M.; Takechi, M.; Fukuda, M.; Nishimura, D.; Suzuki, T.; Matsumoto, T.; Shimizu, Y. R.; Yahiro, M.</p> <p>2014-04-01</p> <p>We analyze recently measured total reaction cross sections for 24-38Mg isotopes incident on 12C targets at 240 MeV/nucleon by using the folding model and antisymmetrized molecular dynamics (AMD). The folding model well reproduces the measured reaction cross sections, when the projectile densities are evaluated by the deformed Woods-Saxon (def-WS) model with AMD deformation. Matter radii of 24-38Mg are then deduced from the measured reaction cross sections by fine tuning the parameters of the def-WS model. The deduced matter radii are largely enhanced by nuclear deformation. Fully microscopic AMD calculations with no free parameter well reproduce the deduced matter radii for 24-36Mg, but still considerably underestimate them for 37,38Mg. The large matter radii suggest that 37,38Mg are candidates for deformed halo nucleus. AMD also reproduces other existing measured <span class="hlt">ground-state</span> properties (spin parity, total binding <span class="hlt">energy</span>, and one-neutron separation <span class="hlt">energy</span>) of Mg isotopes. Neutron-number (N) dependence of deformation parameter is predicted by AMD. Large deformation is seen from 31Mg with N =19 to a drip-line nucleus 40Mg with N =28, indicating that both the N =20 and 28 magicities disappear. N dependence of neutron skin thickness is also predicted by AMD.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SuScT..29g5010C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SuScT..29g5010C"><span>Tunable <span class="hlt">ground</span> <span class="hlt">states</span> in helical p-wave Josephson junctions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, Qiang; Zhang, Kunhua; Yu, Dongyang; Chen, Chongju; Zhang, Yinhan; Jin, Biao</p> <p>2016-07-01</p> <p>We study new types of Josephson junctions composed of helical p-wave superconductors with {k}x\\hat{x}+/- {k}y\\hat{y} and {k}y\\hat{x}+/- {k}x\\hat{y}-pairing symmetries using quasi-classical Green’s functions with generalized Riccati parametrization. The junctions can host rich <span class="hlt">ground</span> <span class="hlt">states</span>: π phase, 0 + π phase, φ 0 phase and φ phase. The phase transition can be tuned by rotating the magnetization in the ferromagnetic interface. We present the phase diagrams in the parameter space formed by the orientation of the magnetization or by the magnitude of the interfacial potentials. The selection rules for the lowest order current which are responsible for the formation of the rich phases are summarized from the current-phase relations based on the numerical calculation. We construct a Ginzburg-Landau type of free <span class="hlt">energy</span> for the junctions with d-vectors and the magnetization, which not only reveals the interaction forms of spin-triplet superconductivity and ferromagnetism, but can also directly lead to the selection rules. In addition, the <span class="hlt">energies</span> of the Andreev bound states and the novel symmetries in the current-phase relations are also investigated. Our results are helpful both in the prediction of novel Josephson phases and in the design of quantum circuits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..93r4415K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..93r4415K"><span><span class="hlt">Ground</span> <span class="hlt">state</span> of Ho atoms on Pt(111) metal surfaces: Implications for magnetism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karbowiak, M.; Rudowicz, C.</p> <p>2016-05-01</p> <p>We investigated the <span class="hlt">ground</span> <span class="hlt">state</span> of Ho atoms adsorbed on the Pt(111) surface, for which conflicting results exist. The density functional theory (DFT) calculations yielded the Ho <span class="hlt">ground</span> <span class="hlt">state</span> as | Jz=±8 > . Interpretation of x-ray absorption spectroscopy and x-ray magnetic circular dichroism spectra and the magnetization curves indicated the <span class="hlt">ground</span> <span class="hlt">state</span> as | Jz=±6 > . Superposition model is employed to predict the crystal-field (CF) parameters based on the structural data for the system Ho/Pt(111) obtained from the DFT modeling. Simultaneous diagonalization of the free-ion (HFI) and the trigonal CF Hamiltonian (HCF) within the whole configuration 4 f10 of H o3 + ion was performed. The role of the trigonal CF terms, neglected in the pure uniaxial CF model used previously for interpretation of experimental spectra, is found significant, whereas the sixth-rank CF terms may be neglected in agreement with the DFT predictions. The results provide substantial support for the experimental designation of the | Jz=±6 > <span class="hlt">ground</span> <span class="hlt">state</span>, albeit with subtle difference due to admixture of other | Jz> states, but run against the DFT-based designation of the | Jz=±8 > <span class="hlt">ground</span> <span class="hlt">state</span>. A subtle splitting of the ground <span class="hlt">energy</span> level with the state (predominantly), | Jz=±6 > is predicted. This paper provides better insight into the single-ion magnetic behavior of the Ho/Pt(111) system by helping to resolve the controversy concerning the Ho <span class="hlt">ground</span> <span class="hlt">state</span>. Experimental techniques with greater resolution powers are suggested for direct confirmation of this splitting and C3 v symmetry experienced by the Ho atom.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1003797','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1003797"><span>Approximating the <span class="hlt">ground</span> <span class="hlt">state</span> of gapped quantum spin systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Michalakis, Spyridon; Hamza, Eman; Nachtergaele, Bruno; Sims, Robert</p> <p>2009-01-01</p> <p>We consider quantum spin systems defined on finite sets V equipped with a metric. In typical examples, V is a large, but finite subset of Z{sup d}. For finite range Hamiltonians with uniformly bounded interaction terms and a unique, gapped <span class="hlt">ground</span> <span class="hlt">state</span>, we demonstrate a locality property of the corresponding <span class="hlt">ground</span> <span class="hlt">state</span> projector. In such systems, this <span class="hlt">ground</span> <span class="hlt">state</span> projector can be approximated by the product of observables with quantifiable supports. In fact, given any subset {chi} {contained_in} V the <span class="hlt">ground</span> <span class="hlt">state</span> projector can be approximated by the product of two projections, one supported on {chi} and one supported on {chi}{sup c}, and a bounded observable supported on a boundary region in such a way that as the boundary region increases, the approximation becomes better. Such an approximation was useful in proving an area law in one dimension, and this result corresponds to a multi-dimensional analogue.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23581301','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23581301"><span><span class="hlt">Ground</span> <span class="hlt">states</span> of the spin-1 Bose-Hubbard model.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Katsura, Hosho; Tasaki, Hal</p> <p>2013-03-29</p> <p>We prove basic theorems about the <span class="hlt">ground</span> <span class="hlt">states</span> of the S=1 Bose-Hubbard model. The results are quite universal and depend only on the coefficient U2 of the spin-dependent interaction. We show that the <span class="hlt">ground</span> <span class="hlt">state</span> exhibits saturated ferromagnetism if U2<0, is spin-singlet if U2>0, and exhibits "SU(3)-ferromagnetism" if U2=0, and completely determine the degeneracy in each region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18518481','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18518481"><span>Theory of <span class="hlt">ground</span> <span class="hlt">state</span> factorization in quantum cooperative systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Giampaolo, Salvatore M; Adesso, Gerardo; Illuminati, Fabrizio</p> <p>2008-05-16</p> <p>We introduce a general analytic approach to the study of factorization points and factorized <span class="hlt">ground</span> <span class="hlt">states</span> in quantum cooperative systems. The method allows us to determine rigorously the existence, location, and exact form of separable <span class="hlt">ground</span> <span class="hlt">states</span> in a large variety of, generally nonexactly solvable, spin models belonging to different universality classes. The theory applies to translationally invariant systems, irrespective of spatial dimensionality, and for spin-spin interactions of arbitrary range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1243180-negative-ion-photoelectron-spectroscopy-confirms-prediction-carbontrioxide-co3-has-singlet-ground-state','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1243180-negative-ion-photoelectron-spectroscopy-confirms-prediction-carbontrioxide-co3-has-singlet-ground-state"><span>Negative Ion Photoelectron Spectroscopy Confirms the Prediction that D-3h Carbontrioxide (CO3) Has a Singlet <span class="hlt">Ground</span> <span class="hlt">State</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Hrovat, David; Hou, Gao-Lei; Chen, Bo; ...</p> <p>2015-11-13</p> <p>The CO3 radical anion (CO3•–) has been formed by electrospraying carbonate dianion (CO32–) into the gas phase. The negative ion photoelectron (NIPE) spectrum of CO3•– shows that, unlike trimethylenemethane [C(CH2)3], carbontrioxide (CO3) has a singlet <span class="hlt">ground</span> <span class="hlt">state</span>. From the NIPE spectrum, the electron affinity of CO3 was determined to be EA = 4.06 ± 0.03 eV, and the singlet-triplet <span class="hlt">energy</span> difference was found to be ΔEST = - 17.8 ± 0.9 kcal/mol. B3LYP, CCSD(T), and CASPT2 calculations all find that the two lowest triplet states of CO3 are very close in <span class="hlt">energy</span>, a prediction that is confirmed by the relativemore » intensities of the <span class="hlt">bands</span> in the NIPE spectrum of CO3•–. The 560 cm-1 vibrational progression, seen in the low <span class="hlt">energy</span> region of the triplet <span class="hlt">band</span>, enables the identification of the lowest, Jahn-Teller-distorted, triplet state as 3A1, in which both unpaired electrons reside in σ MOs, rather than 3A2, in which one unpaired electron occupies the b2 σ MO, and the other occupies the b1 π MO.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MAR.X3001T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MAR.X3001T"><span>Ensemble Theory for Stealthy Hyperuniform Disordered <span class="hlt">Ground</span> <span class="hlt">States</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Torquato, Salvatore</p> <p></p> <p>Disordered hyperuniform many-particle systems have been receiving recent attention because they are distinguishable exotic states of matter poised between a crystal and liquid that are endowed with novel thermodynamic and physical properties. It has been shown numerically that systems of particles interacting with ``stealthy'' bounded, long-ranged pair potentials (similar to Friedel oscillations) have classical <span class="hlt">ground</span> <span class="hlt">states</span> that are, counterintuitively, disordered, hyperuniform and highly degenerate. The task of formulating an ensemble theory that yields analytical predictions for the structural characteristics and other properties of stealthy degenerate <span class="hlt">ground</span> <span class="hlt">states</span> in d-dimensional Euclidean space is highly nontrivial because the dimensionality of the configuration space depends on the number density and there is a multitude of ways of sampling the <span class="hlt">ground-state</span> manifold, each with its own probability measure for finding a particular <span class="hlt">ground-state</span> configuration. A new type of statistical-mechanical theory had to be invented to characterize these exotic states of matter. I report on some initial progress that we have made in this direction. We show that stealthy disordered <span class="hlt">ground</span> <span class="hlt">states</span> behave like ''pseudo''-equilibrium hard-sphere systems in Fourier space. Our theoretical predictions for the structure and thermodynamic properties of the stealthy disordered <span class="hlt">ground</span> <span class="hlt">states</span> and associated excited states are in excellent agreement with computer simulations across dimensions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MAR.G1234C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MAR.G1234C"><span><span class="hlt">Ground</span> <span class="hlt">state</span> configurations in two-mode quantum Rabi models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chilingaryan, Suren; Rodríguez-Lara, B. M.</p> <p></p> <p>We study two models describing a single two-level system coupled to two boson field modes in either a parallel or orthogonal configuration. Both models may be feasible for experimental realization through Raman adiabatic driving in cavity QED. We study their <span class="hlt">ground</span> <span class="hlt">state</span> configurations; that is, we find the quantum precursors of the corresponding semi-classical phase transitions. We found that the <span class="hlt">ground</span> <span class="hlt">state</span> configurations of both models present the same critical coupling as the quantum Rabi model. Around this critical coupling, the <span class="hlt">ground</span> <span class="hlt">state</span> goes from the so-called normal configuration with no excitation, the qubit in the <span class="hlt">ground</span> <span class="hlt">state</span> and the fields in the quantum vacuum state, to a <span class="hlt">ground</span> <span class="hlt">state</span> with excitations, the qubit in a superposition of ground and excited state, while the fields are not in the vacuum anymore, for the first model. The second model shows a more complex <span class="hlt">ground</span> <span class="hlt">state</span> configuration landscape where we find the normal configuration mentioned above, two single-mode configurations, where just one of the fields and the qubit are excited, and a dual-mode configuration, where both fields and the qubit are excited. S A Chilingaryan acknowledges financial support from CONACYT.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22251356','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22251356"><span>A global ab initio potential <span class="hlt">energy</span> surface for the X{sup  2}A{sup ′} <span class="hlt">ground</span> <span class="hlt">state</span> of the Si + OH → SiO + H reaction</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dayou, Fabrice; Duflot, Denis; Rivero-Santamaría, Alejandro; Monnerville, Maurice</p> <p>2013-11-28</p> <p>We report the first global potential <span class="hlt">energy</span> surface (PES) for the X{sup  2}A{sup ′} ground electronic state of the Si({sup 3}P) + OH(X{sup 2}Π) → SiO(X{sup 1}Σ{sub g}{sup +}) + H({sup 2}S) reaction. The PES is based on a large number of ab initio <span class="hlt">energies</span> obtained from multireference configuration interaction calculations plus Davidson correction (MRCI+Q) using basis sets of quadruple zeta quality. Corrections were applied to the ab initio <span class="hlt">energies</span> in the reactant channel allowing a proper description of long-range interactions between Si({sup 3}P) and OH(X{sup 2}Π). An analytical representation of the global PES has been developed by means of the reproducing kernel Hilbert space method. The reaction is found barrierless. Two minima, corresponding to the SiOH and HSiO isomers, and six saddle points, among which the isomerization transition state, have been characterized on the PES. The vibrational spectra of the SiOH/HSiO radicals have been computed from second-order perturbation theory and quantum dynamics methods. The structural, energetic, and spectroscopic properties of the two isomers are in good agreement with experimental data and previous high quality calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910055819&hterms=Recombination&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DRecombination','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910055819&hterms=Recombination&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DRecombination"><span>Dissociative recombination of the <span class="hlt">ground</span> <span class="hlt">state</span> of N2(+)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Guberman, Steven L.</p> <p>1991-01-01</p> <p>Large-scale calculations of the dissociative recombination cross sections and rates for the v = 0 level of the N2(+) <span class="hlt">ground</span> <span class="hlt">state</span> are reported, and the important role played by vibrationally excited Rydberg states lying both below and above the v = 0 level of the ion is demonstrated. The large-scale electronic wave function calculations were done using triple zeta plus polarization nuclear-centered-valence Gaussian basis sets. The electronic widths were obtained using smaller wave functions, and the cross sections were calculated on the basis of the multichannel quantum defect theory. The DR rate is calculated at 1.6 x 10 to the -7th x (Te/300) to the -0.37 cu cm/sec for Te in the range of 100 to 1000 K, and is found to be in excellent agreement with prior microwave afterglow experiments but in disagreement with recent merged beam results. It is inferred that the dominant mechanism for DR imparts sufficient <span class="hlt">energy</span> to the product atoms to allow for escape from the Martian atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvC..91c4330M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvC..91c4330M"><span>Observation of γ vibrations and alignments built on non-<span class="hlt">ground-state</span> configurations in 156Dy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Majola, S. N. T.; Hartley, D. J.; Riedinger, L. L.; Sharpey-Schafer, J. F.; Allmond, J. M.; Beausang, C.; Carpenter, M. P.; Chiara, C. J.; Cooper, N.; Curien, D.; Gall, B. J. P.; Garrett, P. E.; Janssens, R. V. F.; Kondev, F. G.; Kulp, W. D.; Lauritsen, T.; McCutchan, E. A.; Miller, D.; Piot, J.; Redon, N.; Riley, M. A.; Simpson, J.; Stefanescu, I.; Werner, V.; Wang, X.; Wood, J. L.; Yu, C.-H.; Zhu, S.</p> <p>2015-03-01</p> <p>The exact nature of the lowest Kπ=2+ rotational <span class="hlt">bands</span> in all deformed nuclei remains obscure. Traditionally they are assumed to be collective vibrations of the nuclear shape in the γ degree of freedom perpendicular to the nuclear symmetry axis. Very few such γ <span class="hlt">bands</span> have been traced past the usual backbending rotational alignments of high-j nucleons. We have investigated the structure of positive-parity <span class="hlt">bands</span> in the N =90 nucleus 156Dy , using the 148Nd(12C,4 n ) 156Dy reaction at 65 MeV, observing the resulting γ-ray transitions with the Gammasphere array. The even- and odd-spin members of the Kπ=2+ γ <span class="hlt">band</span> are observed up to 32+ and 31+, respectively. This rotational <span class="hlt">band</span> faithfully tracks the <span class="hlt">ground-state</span> configuration to the highest spins. The members of a possible γ vibration built on the aligned yrast S <span class="hlt">band</span> are observed up to spins 28+ and 27+. An even-spin positive-parity <span class="hlt">band</span>, observed up to spin 24+, is a candidate for an aligned S <span class="hlt">band</span> built on the seniority-zero configuration of the 02+ state at 676 keV. The crossing of this <span class="hlt">band</span> with the 02+ <span class="hlt">band</span> is at ℏ ωc=0.28 (1 ) MeV and is consistent with the configuration of the 02+ <span class="hlt">band</span> not producing any blocking of the monopole pairing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26918977','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26918977"><span><span class="hlt">Ground</span> <span class="hlt">State</span> of the Universe and the Cosmological Constant. A Nonperturbative Analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Husain, Viqar; Qureshi, Babar</p> <p>2016-02-12</p> <p>The physical Hamiltonian of a gravity-matter system depends on the choice of time, with the vacuum naturally identified as its <span class="hlt">ground</span> <span class="hlt">state</span>. We study the expanding Universe with scalar field in the volume time gauge. We show that the vacuum <span class="hlt">energy</span> density computed from the resulting Hamiltonian is a nonlinear function of the cosmological constant and time. This result provides a new perspective on the relation between time, the cosmological constant, and vacuum <span class="hlt">energy</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT........86C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT........86C"><span>Nanoscale Studies of <span class="hlt">Energy</span> <span class="hlt">Band</span> Gaps and <span class="hlt">Band</span> Offsets in Compound Semiconductor Heterostructures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Alexander S.</p> <p></p> <p>The identification of the precise <span class="hlt">band</span> offsets at semiconductor interfaces is crucially important for the successful development of electronic and optoelectronic devices. However, issues at the interfaces, such as strain or defects, needs to be investigated for precise <span class="hlt">band</span> tuning of semiconductor heterostructures. In this dissertation, the nanometer-scale structural and electronic properties of InGaAs(Sb)N/GaAs interfaces, InGaN/GaN QDs, and GaSb/GaAs QDs are investigated using a combination of XSTM and STS. The influence of Sb incorporation on the InGaAs(Sb)N/GaAs <span class="hlt">band</span> alignment is investigated. At the InGaAsN/GaAs (InGaAsSbN/GaAs) interfaces, type II (type I) <span class="hlt">band</span> offsets are observed, due to strain-induced splitting of the valence <span class="hlt">band</span> and the incorporation of Sb. <span class="hlt">Band</span> tuning of both conduction and valence <span class="hlt">band</span> edges with the incorporation of Sb can be used to engineer the <span class="hlt">band</span> structure with strong confinement of electrons and holes in the InGaAsSbN quantum well layer, which is promising for light emitting applications. The influence of the growth substrate on InGaN/GaN QD formation and properties is examined. The QD density, dimension, and <span class="hlt">band</span> gaps are compared for different InGaN QDs on free-standing GaN or GaN/AlN/sapphire substrates. We present different sources using nucleation on different substrates, and discuss their influences on the electronic <span class="hlt">band</span> structure. Our work suggests that a wide variety of InGaN QD dimension, density, and <span class="hlt">band</span> structure can be achieved by using different starting substrate and number of layers of InGaN QD stacks. Furthermore, the influence of strain and dislocation on the GaSb/GaAs QD <span class="hlt">band</span> alignment is investigated using both experimental and computational tools. A combination of cross-sectional transmission electron microscopy (XTEM), XSTM, and STS reveals the formation of misfit dislocations and both coherent and semi-coherent clustered QDs, independent of Sb- vs. As-termination of the GaAs surface. Furthermore, finite</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=%22light-emitting+diode%22+OR+lighting&pg=3&id=EJ829407','ERIC'); return false;" href="https://eric.ed.gov/?q=%22light-emitting+diode%22+OR+lighting&pg=3&id=EJ829407"><span>Simple Experimental Verification of the Relation between the <span class="hlt">Band</span>-Gap <span class="hlt">Energy</span> and the <span class="hlt">Energy</span> of Photons Emitted by LEDs</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Precker, Jurgen W.</p> <p>2007-01-01</p> <p>The wavelength of the light emitted by a light-emitting diode (LED) is intimately related to the <span class="hlt">band</span>-gap <span class="hlt">energy</span> of the semiconductor from which the LED is made. We experimentally estimate the <span class="hlt">band</span>-gap <span class="hlt">energies</span> of several types of LEDs, and compare them with the <span class="hlt">energies</span> of the emitted light, which ranges from infrared to white. In spite of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=%22light-emitting+diode%22+OR+lighting&pg=3&id=EJ829407','ERIC'); return false;" href="http://eric.ed.gov/?q=%22light-emitting+diode%22+OR+lighting&pg=3&id=EJ829407"><span>Simple Experimental Verification of the Relation between the <span class="hlt">Band</span>-Gap <span class="hlt">Energy</span> and the <span class="hlt">Energy</span> of Photons Emitted by LEDs</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Precker, Jurgen W.</p> <p>2007-01-01</p> <p>The wavelength of the light emitted by a light-emitting diode (LED) is intimately related to the <span class="hlt">band</span>-gap <span class="hlt">energy</span> of the semiconductor from which the LED is made. We experimentally estimate the <span class="hlt">band</span>-gap <span class="hlt">energies</span> of several types of LEDs, and compare them with the <span class="hlt">energies</span> of the emitted light, which ranges from infrared to white. In spite of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvC..96c4301C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvC..96c4301C"><span><span class="hlt">Ground-state</span> configuration of neutron-rich 35Al via Coulomb breakup</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chakraborty, S.; Datta, Ushasi; Aumann, T.; Beceiro-Novo, S.; Boretzky, K.; Caesar, C.; Carlson, B. V.; Catford, W. N.; Chartier, M.; Cortina-Gil, D.; De Angelis, G.; Fernandez, P. Diaz; Emling, H.; Ershova, O.; Fraile, L. M.; Geissel, H.; Gonzalez-Diaz, D.; Johansson, H.; Jonson, B.; Kalantar-Nayestanaki, N.; Kröll, T.; Krücken, R.; Langer, C.; Le Bleis, T.; Leifels, Y.; Marganiec, J.; Münzenberg, G.; Najafi, M. A.; Nilsson, T.; Nociforo, C.; Panin, V.; Plag, R.; Rahaman, A.; Reifarth, R.; Ricciardi, M. V.; Rigollet, C.; Rossi, D.; Scheidenberger, C.; Scheit, H.; Simon, H.; Taylor, J. T.; Togano, Y.; Typel, S.; Utsuno, Y.; Wagner, A.; Wamers, F.; Weick, H.; Winfield, J. S.</p> <p>2017-09-01</p> <p>The <span class="hlt">ground-state</span> configuration of 35Al has been studied via Coulomb dissociation (CD) using the LAND-FRS setup (GSI, Darmstadt) at a relativistic <span class="hlt">energy</span> of ˜403 MeV/nucleon. The measured inclusive differential CD cross section for 35Al, integrated up to 5.0 MeV relative <span class="hlt">energy</span> between the 34Al core and the neutron using a Pb target, is 78(13) mb. The exclusive measured CD cross section that populates various excited states of 34Al is 29(7) mb. The differential CD cross section of 35Al→34Al+n has been interpreted in the light of a direct breakup model, and it suggests that the possible <span class="hlt">ground-state</span> spin and parity of 35Al could be, tentatively, 1 /2+ or 3 /2+ or 5 /2+ . The valence neutrons, in the <span class="hlt">ground</span> <span class="hlt">state</span> of 35Al, may occupy a combination of either l =3 ,0 or l =1 ,2 orbitals coupled with the 34Al core in the ground and isomeric state(s), respectively. This hints of a particle-hole configuration of the neutron across the magic shell gaps at N =20 ,28 which suggests narrowing the magic shell gap. If the 5 /2+ is the <span class="hlt">ground-state</span> spin-parity of 35Al as suggested in the literature, then the major <span class="hlt">ground-state</span> configuration of 35Al is a combination of 34Al(g.s.;4-) ⊗νp3/2 and 34Al(isomer;1+) ⊗νd3/2 states. The result from this experiment has been compared with that from a previous knockout measurement and a calculation using the SDPF-M interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatCo...710484S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatCo...710484S"><span>Magnetic <span class="hlt">ground</span> <span class="hlt">state</span> of an individual Fe2+ ion in strained semiconductor nanostructure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smoleński, T.; Kazimierczuk, T.; Kobak, J.; Goryca, M.; Golnik, A.; Kossacki, P.; Pacuski, W.</p> <p>2016-01-01</p> <p>Single impurities with nonzero spin and multiple <span class="hlt">ground</span> <span class="hlt">states</span> offer a degree of freedom that can be utilized to store the quantum information. However, Fe2+ dopant is known for having a single nondegenerate <span class="hlt">ground</span> <span class="hlt">state</span> in the bulk host semiconductors and thus is of little use for spintronic applications. Here we show that the well-established picture of Fe2+ spin configuration can be modified by subjecting the Fe2+ ion to high strain, for example, produced by lattice mismatched epitaxial nanostructures. Our analysis reveals that high strain induces qualitative change in the ion <span class="hlt">energy</span> spectrum and results in nearly doubly degenerate <span class="hlt">ground</span> <span class="hlt">state</span> with spin projection Sz=+/-2. We provide an experimental proof of this concept using a new system: a strained epitaxial quantum dot containing individual Fe2+ ion. Magnetic character of the Fe2+ <span class="hlt">ground</span> <span class="hlt">state</span> in a CdSe/ZnSe dot is revealed in photoluminescence experiments by exploiting a coupling between a confined exciton and the single-iron impurity. We also demonstrate that the Fe2+ spin can be oriented by spin-polarized excitons, which opens a possibility of using it as an optically controllable two-level system free of nuclear spin fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4738340','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4738340"><span>Magnetic <span class="hlt">ground</span> <span class="hlt">state</span> of an individual Fe2+ ion in strained semiconductor nanostructure</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Smoleński, T.; Kazimierczuk, T.; Kobak, J.; Goryca, M.; Golnik, A.; Kossacki, P.; Pacuski, W.</p> <p>2016-01-01</p> <p>Single impurities with nonzero spin and multiple <span class="hlt">ground</span> <span class="hlt">states</span> offer a degree of freedom that can be utilized to store the quantum information. However, Fe2+ dopant is known for having a single nondegenerate <span class="hlt">ground</span> <span class="hlt">state</span> in the bulk host semiconductors and thus is of little use for spintronic applications. Here we show that the well-established picture of Fe2+ spin configuration can be modified by subjecting the Fe2+ ion to high strain, for example, produced by lattice mismatched epitaxial nanostructures. Our analysis reveals that high strain induces qualitative change in the ion <span class="hlt">energy</span> spectrum and results in nearly doubly degenerate <span class="hlt">ground</span> <span class="hlt">state</span> with spin projection Sz=±2. We provide an experimental proof of this concept using a new system: a strained epitaxial quantum dot containing individual Fe2+ ion. Magnetic character of the Fe2+ <span class="hlt">ground</span> <span class="hlt">state</span> in a CdSe/ZnSe dot is revealed in photoluminescence experiments by exploiting a coupling between a confined exciton and the single-iron impurity. We also demonstrate that the Fe2+ spin can be oriented by spin-polarized excitons, which opens a possibility of using it as an optically controllable two-level system free of nuclear spin fluctuations. PMID:26818580</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3693153','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3693153"><span>Enhancement of Vibronic and <span class="hlt">Ground-State</span> Vibrational Coherences in 2D Spectra of Photosynthetic Complexes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chenu, Aurélia; Christensson, Niklas; Kauffmann, Harald F.; Mančal, Tomáš</p> <p>2013-01-01</p> <p>A vibronic-exciton model is applied to investigate the recently proposed mechanism of enhancement of coherent oscillations due to mixing of electronic and nuclear degrees of freedom. We study a dimer system to elucidate the role of resonance coupling, site <span class="hlt">energies</span>, vibrational frequency and <span class="hlt">energy</span> disorder in the enhancement of vibronic-exciton and <span class="hlt">ground-state</span> vibrational coherences, and to identify regimes where this enhancement is significant. For a heterodimer representing two coupled bachteriochloropylls of the FMO complex, long-lived vibronic coherences are found to be generated only when the frequency of the mode is in the vicinity of the electronic <span class="hlt">energy</span> difference. Although the vibronic-exciton coherences exhibit a larger initial amplitude compared to the <span class="hlt">ground-state</span> vibrational coherences, we conclude that, due to the dephasing of the former, both type of coherences have a similar magnitude at longer population time. PMID:23778355</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5022608','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5022608"><span>Does a 5/2 sup + -5/2 sup minus <span class="hlt">ground-state</span> parity doublet exist in sup 229 Pa</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Grafen, V.; Ackermann, B.; Baltzer, H.; Bihn, T.; Guenther, C. ); deBoer, J.; Gollwitzer, N.; Graw, G.; Hertenberger, R.; Kader, H.; Levon, A.; Loesch, A. )</p> <p>1991-11-01</p> <p>The 1/2(530) decoupled <span class="hlt">band</span> in {sup 229}Pa has been identified up to the 19/2{sup {minus}} level in ({ital p},{ital t}) and ({ital p},2{ital n}{gamma}) experiments. It is found that the 3/2{sup {minus}} <span class="hlt">band</span> head has an excitation <span class="hlt">energy</span> of 19(10) keV, and can thus not be identified with a 123 keV level observed in the {sup 229}U electron capture decay. This removes the evidence presented earlier for a spin-parity assignment of 5/2{sup +-}5/2{sup {minus}} to a proposed nearly degenerate <span class="hlt">ground-state</span> doublet in {sup 229}Pa.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5763..150M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5763..150M"><span>Bandgaps of zigzag finite-length nanotubes ab initio calculations: <span class="hlt">ground</span> <span class="hlt">state</span> degeneracy and single-electron spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mestechkin, Mikhail; Zubkov, Vladimir</p> <p>2005-05-01</p> <p>Different versions of ab initio quantum chemical models (cluster and periodic boundary conditions approximations) have been used to analyze the effect of finite length and the partial filling of the highest occupied orbital on the <span class="hlt">band</span>-gaps of carbon nanotubes. In agreement with the previous calculations in the tight-binding approximation and pi-electron open shell model, it has been shown that the <span class="hlt">ground</span> <span class="hlt">state</span> of the nanotube with the zigzag structure is triplet. It has been confirmed that these tubes exhibit metallic or semiconductor properties with a very narrow half-filled conduction <span class="hlt">band</span>. The <span class="hlt">band</span>-gap is of order few tens of eV, and it is estimated that approximately 0.1-0.2% of pi-electrons belong to the conduction <span class="hlt">band</span> of finite zigzag nanotubes. The triplet state is predicted to be the <span class="hlt">ground</span> <span class="hlt">state</span> of finite-length carbon nanotubes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996CP....211..191K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996CP....211..191K"><span>Potential <span class="hlt">energy</span> curve of the X0 +( 1Σ ++) <span class="hlt">ground</span> <span class="hlt">state</span> of HgAr determined from A0 +( 3Π) → X0 +andB1( 3Σ + → X0 + fluorescence spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koperski, J.</p> <p>1996-11-01</p> <p>A0 +( 3Π) → X0 +( 1Σ +) andB1( 3Σ +) → X0 +( 1Σ +) fluorescence spectra of HgAr van der Waals molecules were previously produced in a pulsed supersonic molecular beam crossed with a pulsed dye-laser beam, following excitation of single vibronic levels. The dispersed fluorescence displayed characteristic Condon internal diffraction (CID) patterns consisting of bound-free reflection type, continuous spectra, and also bound-bound discrete features. An analysis of the A O+ → X0 + and B1 → X O+ bound-bound spectra indicates that a Morese function is an adequate representatation of the X0 + potential <span class="hlt">energy</span> (PE) curve below the dissociation limit. In simulation of the A O+ → X0 + bound-free spectra of the Morse, Lennard-Jones ( n - 6) and Maitland-Smith functions were tested, and the Maitland-Smith potential was found to be a good representation of the repulsive wall of the X0 + PE curve above the dissociation limit over the internuclear separation range R = 2.8-3.5 Å.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013CP....412...58P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013CP....412...58P"><span>Geometrical criteria versus quantum chemical criteria for assessment of intramolecular hydrogen bond (IMHB) interaction: A computational comparison into the effect of chlorine substitution on IMHB of salicylic acid in its lowest <span class="hlt">energy</span> <span class="hlt">ground</span> <span class="hlt">state</span> conformer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paul, Bijan Kumar; Guchhait, Nikhil</p> <p>2013-02-01</p> <p>Density functional theory based computational study has been performed to characterize intramolecular hydrogen bonding (IMHB) interaction in a series of salicylic acid derivatives varying in chlorine substitution on the benzene ring. The molecular systems studied are salicylic acid, 5-chlorosalicylic acid, 3,5-dichlorosalicylic acid and 3,5,6-tricholorosalicylic acid. Major emphasis is rendered on the analysis of IMHB interaction by calculation of electron density ρ(r) and Laplacian ∇2ρ(r) at the bond critical point using atoms-in-molecule theory. Topological features, <span class="hlt">energy</span> densities based on ρ(r) through perturbing the intramolecular H-bond distances suggest that at equilibrium geometry the IMHB interaction develops certain characteristics typical of covalent interaction. The interplay between aromaticity and resonance-assisted hydrogen bonding (RAHB) is discussed using both geometrical and magnetic criteria as the descriptors of aromaticity. The optimized geometry features, molecular electrostatic potential map analysis are also found to produce a consensus view in relation with the formation of RAHB in these systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22490434','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22490434"><span>Electronic structure and <span class="hlt">ground-state</span> properties of Na{sub 2}Po: A first-principles study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Eithiraj, R. D.</p> <p>2015-06-24</p> <p>Self-consistent scalar-relativistic <span class="hlt">band</span> structure calculations have been performed to investigate the electronic structure and <span class="hlt">ground-state</span> properties of Na{sub 2}Po in cubic antifluorite (anti-CaF{sub 2}-type) structure using the linear muffin-tin orbital in its tight-binding representation (TB-LMTO) method. <span class="hlt">Ground</span> <span class="hlt">state</span> properties such as equilibrium lattice constant and bulk modulus were calculated. The results of the electronic structure calculations show that Na{sub 2}Po is direct bandgap semiconductor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3216574','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3216574"><span>Solving Quantum <span class="hlt">Ground-State</span> Problems with Nuclear Magnetic Resonance</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Zhaokai; Yung, Man-Hong; Chen, Hongwei; Lu, Dawei; Whitfield, James D.; Peng, Xinhua; Aspuru-Guzik, Alán; Du, Jiangfeng</p> <p>2011-01-01</p> <p>Quantum <span class="hlt">ground-state</span> problems are computationally hard problems for general many-body Hamiltonians; there is no classical or quantum algorithm known to be able to solve them efficiently. Nevertheless, if a trial wavefunction approximating the <span class="hlt">ground</span> <span class="hlt">state</span> is available, as often happens for many problems in physics and chemistry, a quantum computer could employ this trial wavefunction to project the <span class="hlt">ground</span> <span class="hlt">state</span> by means of the phase estimation algorithm (PEA). We performed an experimental realization of this idea by implementing a variational-wavefunction approach to solve the <span class="hlt">ground-state</span> problem of the Heisenberg spin model with an NMR quantum simulator. Our iterative phase estimation procedure yields a high accuracy for the eigenenergies (to the 10−5 decimal digit). The <span class="hlt">ground-state</span> fidelity was distilled to be more than 80%, and the singlet-to-triplet switching near the critical field is reliably captured. This result shows that quantum simulators can better leverage classical trial wave functions than classical computers PMID:22355607</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvA..95a2121G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvA..95a2121G"><span>Quench of a symmetry-broken <span class="hlt">ground</span> <span class="hlt">state</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Giampaolo, S. M.; Zonzo, G.</p> <p>2017-01-01</p> <p>We analyze the problem of how different <span class="hlt">ground</span> <span class="hlt">states</span> associated with the same set of Hamiltonian parameters evolve after a sudden quench. To realize our analysis we define a quantitative approach to the local distinguishability between different <span class="hlt">ground</span> <span class="hlt">states</span> of a magnetically ordered phase in terms of the trace distance between the reduced density matrices obtained by projecting two <span class="hlt">ground</span> <span class="hlt">states</span> in the same subset. Before the quench, regardless of the particular choice of subset, any system in a magnetically ordered phase is characterized by <span class="hlt">ground</span> <span class="hlt">states</span> that are locally distinguishable. On the other hand, after the quench, the maximum distinguishability shows an exponential decay in time. Hence, in the limit of very long times, all the information about the particular initial <span class="hlt">ground</span> <span class="hlt">state</span> is lost even if the systems are integrable. We prove our claims in the framework of the magnetically ordered phases that characterize both the X Y and the N -cluster Ising models. The fact that we find similar behavior in models within different classes of symmetry makes us confident about the generality of our results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22093434','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22093434"><span>Importance of complex orbitals in calculating the self-interaction-corrected <span class="hlt">ground</span> <span class="hlt">state</span> of atoms</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kluepfel, Simon; Kluepfel, Peter; Jonsson, Hannes</p> <p>2011-11-15</p> <p>The <span class="hlt">ground</span> <span class="hlt">state</span> of atoms from H to Ar was calculated using a self-interaction correction to local- and gradient-dependent density functionals. The correction can significantly improve the total <span class="hlt">energy</span> and makes the orbital <span class="hlt">energies</span> consistent with ionization <span class="hlt">energies</span>. However, when the calculation is restricted to real orbitals, application of the self-interaction correction can give significantly higher total <span class="hlt">energy</span> and worse results, as illustrated by the case of the Perdew-Burke-Ernzerhof gradient-dependent functional. This illustrates the importance of using complex orbitals for systems described by orbital-density-dependent <span class="hlt">energy</span> functionals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22489564','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22489564"><span>Determining the <span class="hlt">band</span> gap and mean kinetic <span class="hlt">energy</span> of atoms from reflection electron <span class="hlt">energy</span> loss spectra</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vos, M.; Marmitt, G. G.; Finkelstein, Y.; Moreh, R.</p> <p>2015-09-14</p> <p>Reflection electron <span class="hlt">energy</span> loss spectra from some insulating materials (CaCO{sub 3}, Li{sub 2}CO{sub 3}, and SiO{sub 2}) taken at relatively high incoming electron <span class="hlt">energies</span> (5–40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the <span class="hlt">band</span> gap. An estimate of the <span class="hlt">band</span> gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic <span class="hlt">energy</span> of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic <span class="hlt">energies</span> of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO{sub 2}, good agreement is obtained with the well-established value of the <span class="hlt">band</span> gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E − E{sub gap}){sup 1.5}. For CaCO{sub 3}, the <span class="hlt">band</span> gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li{sub 2}CO{sub 3} (7.5 eV) is the first experimental estimate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JChPh.143j4203V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JChPh.143j4203V"><span>Determining the <span class="hlt">band</span> gap and mean kinetic <span class="hlt">energy</span> of atoms from reflection electron <span class="hlt">energy</span> loss spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vos, M.; Marmitt, G. G.; Finkelstein, Y.; Moreh, R.</p> <p>2015-09-01</p> <p>Reflection electron <span class="hlt">energy</span> loss spectra from some insulating materials (CaCO3, Li2CO3, and SiO2) taken at relatively high incoming electron <span class="hlt">energies</span> (5-40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the <span class="hlt">band</span> gap. An estimate of the <span class="hlt">band</span> gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic <span class="hlt">energy</span> of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic <span class="hlt">energies</span> of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO2, good agreement is obtained with the well-established value of the <span class="hlt">band</span> gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E - Egap)1.5. For CaCO3, the <span class="hlt">band</span> gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li2CO3 (7.5 eV) is the first experimental estimate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21528583','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21528583"><span><span class="hlt">Ground-state</span> geometric quantum computing in superconducting systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Solinas, P.; Moettoenen, M.</p> <p>2010-11-15</p> <p>We present a theoretical proposal for the implementation of geometric quantum computing based on a Hamiltonian which has a doubly degenerate <span class="hlt">ground</span> <span class="hlt">state</span>. Thus the system which is steered adiabatically, remains in the <span class="hlt">ground-state</span>. The proposed physical implementation relies on a superconducting circuit composed of three SQUIDs and two superconducting islands with the charge states encoding the logical states. We obtain a universal set of single-qubit gates and implement a nontrivial two-qubit gate exploiting the mutual inductance between two neighboring circuits, allowing us to realize a fully geometric <span class="hlt">ground-state</span> quantum computing. The introduced paradigm for the implementation of geometric quantum computing is expected to be robust against environmental effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20867055','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20867055"><span>Probing quantum frustrated systems via factorization of the <span class="hlt">ground</span> <span class="hlt">state</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Giampaolo, Salvatore M; Adesso, Gerardo; Illuminati, Fabrizio</p> <p>2010-05-21</p> <p>The existence of definite orders in frustrated quantum systems is related rigorously to the occurrence of fully factorized <span class="hlt">ground</span> <span class="hlt">states</span> below a threshold value of the frustration. <span class="hlt">Ground-state</span> separability thus provides a natural measure of frustration: strongly frustrated systems are those that cannot accommodate for classical-like solutions. The exact form of the factorized <span class="hlt">ground</span> <span class="hlt">states</span> and the critical frustration are determined for various classes of nonexactly solvable spin models with different spatial ranges of the interactions. For weak frustration, the existence of disentangling transitions determines the range of applicability of mean-field descriptions in biological and physical problems such as stochastic gene expression and the stability of long-period modulated structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARY29005K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARY29005K"><span>Improved fair sampling of <span class="hlt">ground</span> <span class="hlt">states</span> in Ising spin glasses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Katzgraber, Helmut G.; Zhu, Zheng; Ochoa, Andrew J.</p> <p>2015-03-01</p> <p>Verifying that an optimization approach can sample all solutions that minimize a Hamiltonian is a stringent test for any newly-developed algorithm. While most solvers easily compute the minimum of a cost function for small to moderate input sizes, equiprobable sampling of all <span class="hlt">ground-state</span> configurations (within Poissonian fluctuations) is much harder to obtain. Most notably, methods such as transverse-field quantum annealing fail in passing this test for certain highly-degenerate problems. Here we present an attempt to sample <span class="hlt">ground</span> <span class="hlt">states</span> for Ising spin glasses based on a combination of low-temperature parallel tempering Monte Carlo combined with the cluster algorithm by Houdayer. Because the latter is rejection free and obeys details balance, the <span class="hlt">ground-state</span> manifold is efficiently sampled. We illustrate the approach for Ising spin glasses on the D-Wave Two quantum annealer topology, known as the Chimera graph, as well as two-dimensional Ising spin glasses.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JHEP...03..165B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JHEP...03..165B"><span>Magnetic field induced lattice <span class="hlt">ground</span> <span class="hlt">states</span> from holography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bu, Yan-Yan; Erdmenger, Johanna; Shock, Jonathan P.; Strydom, Migael</p> <p>2013-03-01</p> <p>We study the holographic field theory dual of a probe SU(2) Yang-Mills field in a background (4 + 1)-dimensional asymptotically Anti-de Sitter space. We find a new <span class="hlt">ground</span> <span class="hlt">state</span> when a magnetic component of the gauge field is larger than a critical value. The <span class="hlt">ground</span> <span class="hlt">state</span> forms a triangular Abrikosov lattice in the spatial directions perpendicular to the magnetic field. The lattice is composed of superconducting vortices induced by the condensation of a charged vector operator. We perform this calculation both at finite temperature and at zero temperature with a hard wall cutoff dual to a confining gauge theory. The study of this state may be of relevance to both holographic condensed matter models as well as to heavy ion physics. The results shown here provide support for the proposal that such a <span class="hlt">ground</span> <span class="hlt">state</span> may be found in the QCD vacuum when a large magnetic field is present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhA...50K5203G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhA...50K5203G"><span>Topology of time-reversal invariant <span class="hlt">energy</span> <span class="hlt">bands</span> with adiabatic structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gat, Omri; Robbins, J. M.</p> <p>2017-09-01</p> <p>We classify the topology of <span class="hlt">bands</span> defined by the <span class="hlt">energy</span> states of quantum systems with scale separation between slow and fast degrees of freedom, invariant under fermionic time reversal. Classical phase space transforms differently from momentum space under time reversal, and as a consequence the topology of adiabatic <span class="hlt">bands</span> is different from that of Bloch <span class="hlt">bands</span>. We show that <span class="hlt">bands</span> defined over a two-dimensional phase space are classified by the Chern number, whose parity must be equal to the parity of the <span class="hlt">band</span> rank. Even-rank <span class="hlt">bands</span> are equivalently classified by the Kane-Mele index, an integer equal to one half the Chern number.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22181919','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22181919"><span>Diversity enabling equilibration: disorder and the <span class="hlt">ground</span> <span class="hlt">state</span> in artificial spin ice.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Budrikis, Zoe; Politi, Paolo; Stamps, R L</p> <p>2011-11-18</p> <p>We report a novel approach to the question of whether and how the <span class="hlt">ground</span> <span class="hlt">state</span> can be achieved in square artificial spin ices where frustration is incomplete. We identify two sources of randomness that affect the approach to <span class="hlt">ground</span> <span class="hlt">state</span>: quenched disorder in the island response to fields and randomness in the sequence of driving fields. Numerical simulations show that quenched disorder can lead to final states with lower <span class="hlt">energy</span>, and randomness in the sequence of driving fields always lowers the final <span class="hlt">energy</span> attained by the system. We use a network picture to understand these two effects: disorder in island responses creates new dynamical pathways, and a random sequence of driving fields allows more pathways to be followed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JChPh.138t4115K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JChPh.138t4115K"><span>Using optimally tuned range separated hybrid functionals in <span class="hlt">ground-state</span> calculations: Consequences and caveats</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karolewski, Andreas; Kronik, Leeor; Kümmel, Stephan</p> <p>2013-05-01</p> <p>Optimally tuned range separated hybrid functionals are a new class of implicitly defined functionals. Their important new aspect is that the range separation parameter in these functionals is determined individually for each system by iteratively tuning it until a fundamental, non-empirical condition is fulfilled. Such functionals have been demonstrated to be extremely successful in predicting electronic excitations. In this paper, we explore the use of the tuning approach for predicting <span class="hlt">ground</span> <span class="hlt">state</span> properties. This sheds light on one of its downsides - the violation of size consistency. By analyzing diatomic molecules, we reveal size consistency errors up to several electron volts and find that binding <span class="hlt">energies</span> cannot be predicted reliably. Further consequences of the consistent <span class="hlt">ground-state</span> use of the tuning approach are potential <span class="hlt">energy</span> surfaces that are qualitatively in error and an incorrect prediction of spin states. We discuss these failures, their origins, and possibilities for overcoming them.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvB..89d1404M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvB..89d1404M"><span>Boron aggregation in the <span class="hlt">ground</span> <span class="hlt">states</span> of boron-carbon fullerenes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohr, Stephan; Pochet, Pascal; Amsler, Maximilian; Schaefer, Bastian; Sadeghi, Ali; Genovese, Luigi; Goedecker, Stefan</p> <p>2014-01-01</p> <p>We present unexpected structural motifs for boron-carbon nanocages of the stoichiometries B12C48 and B12C50, based on first-principles calculations. These configurations are distinct from those proposed so far because the boron atoms are not isolated and distributed over the entire surface of the cages, but rather aggregate at one location to form a patch. Our putative <span class="hlt">ground</span> <span class="hlt">state</span> of B12C48 is 1.8 eV lower in <span class="hlt">energy</span> than the previously proposed <span class="hlt">ground</span> <span class="hlt">state</span> and violates all the suggested empirical rules for constructing low-<span class="hlt">energy</span> fullerenes. The B12C50 configuration is energetically even more favorable than B12C48, showing that structures derived from the C60 buckminsterfullerene are not necessarily magic sizes for heterofullerenes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22590793','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22590793"><span>High spin polarization and the origin of unique ferromagnetic <span class="hlt">ground</span> <span class="hlt">state</span> in CuFeSb</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sirohi, Anshu; Saha, Preetha; Gayen, Sirshendu; Gaurav, Abhishek; Jyotsna, Shubhra; Sheet, Goutam; Singh, Chandan K.; Kabir, Mukul; Thakur, Gohil S.; Haque, Zeba; Gupta, L. C.; Ganguli, Ashok K.</p> <p>2016-06-13</p> <p>CuFeSb is isostructural to the ferro-pnictide and chalcogenide superconductors and it is one of the few materials in the family that are known to stabilize in a ferromagnetic <span class="hlt">ground</span> <span class="hlt">state</span>. Majority of the members of this family are either superconductors or antiferromagnets. Therefore, CuFeSb may be used as an ideal source of spin polarized current in spin-transport devices involving pnictide and the chalcogenide superconductors. However, for that the Fermi surface of CuFeSb needs to be sufficiently spin polarized. In this paper we report direct measurement of transport spin polarization in CuFeSb by spin-resolved Andreev reflection spectroscopy. From a number of measurements using multiple superconducting tips we found that the intrinsic transport spin polarization in CuFeSb is high (∼47%). In order to understand the unique <span class="hlt">ground</span> <span class="hlt">state</span> of CuFeSb and the origin of large spin polarization at the Fermi level, we have evaluated the spin-polarized <span class="hlt">band</span> structure of CuFeSb through first principles calculations. Apart from supporting the observed 47% transport spin polarization, such calculations also indicate that the Sb-Fe-Sb angles and the height of Sb from the Fe plane are strikingly different for CuFeSb than the equivalent parameters in other members of the same family thereby explaining the origin of the unique <span class="hlt">ground</span> <span class="hlt">state</span> of CuFeSb.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhRvL.100j0502R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhRvL.100j0502R"><span>Highly Entangled <span class="hlt">Ground</span> <span class="hlt">States</span> in Tripartite Qubit Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Röthlisberger, Beat; Lehmann, Jörg; Saraga, D. S.; Traber, Philipp; Loss, Daniel</p> <p>2008-03-01</p> <p>We investigate the creation of highly entangled <span class="hlt">ground</span> <span class="hlt">states</span> in a system of three exchange-coupled qubits arranged in a ring geometry. Suitable magnetic field configurations yielding approximate Greenberger-Horne-Zeilinger and exact W <span class="hlt">ground</span> <span class="hlt">states</span> are identified. The entanglement in the system is studied at finite temperature in terms of the mixed-state tangle τ. By generalizing a conjugate gradient optimization algorithm originally developed to evaluate the entanglement of formation, we demonstrate that τ can be calculated efficiently and with high precision. We identify the parameter regime for which the equilibrium entanglement of the tripartite system reaches its maximum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhRvA..81f2335S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhRvA..81f2335S"><span>Homogeneous binary trees as <span class="hlt">ground</span> <span class="hlt">states</span> of quantum critical Hamiltonians</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Silvi, P.; Giovannetti, V.; Montangero, S.; Rizzi, M.; Cirac, J. I.; Fazio, R.</p> <p>2010-06-01</p> <p>Many-body states whose wave functions admit a representation in terms of a uniform binary-tree tensor decomposition are shown to obey power-law two-body correlation functions. Any such state can be associated with the <span class="hlt">ground</span> <span class="hlt">state</span> of a translationally invariant Hamiltonian which, depending on the dimension of the systems sites, involves at most couplings between third-neighboring sites. Under general conditions it is shown that they describe unfrustrated systems which admit an exponentially large degeneracy of the <span class="hlt">ground</span> <span class="hlt">state</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvB..91b4201Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvB..91b4201Z"><span>From local to global <span class="hlt">ground</span> <span class="hlt">states</span> in Ising spin glasses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zintchenko, Ilia; Hastings, Matthew B.; Troyer, Matthias</p> <p>2015-01-01</p> <p>We consider whether it is possible to find <span class="hlt">ground</span> <span class="hlt">states</span> of frustrated spin systems by solving them locally. Using spin glass physics and Imry-Ma arguments in addition to numerical benchmarks we quantify the power of such local solution methods and show that for the average low-dimensional spin glass problem outside the spin glass phase the exact <span class="hlt">ground</span> <span class="hlt">state</span> can be found in polynomial time. In the second part we present a heuristic, general-purpose hierarchical approach which for spin glasses on chimera graphs and lattices in two and three dimensions outperforms, to our knowledge, any other solver currently around, with significantly better scaling performance than simulated annealing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17358892','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17358892"><span><span class="hlt">Ground</span> <span class="hlt">states</span> of the SU(N) Heisenberg model.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kawashima, Naoki; Tanabe, Yuta</p> <p>2007-02-02</p> <p>The SU(N) Heisenberg model with various single-row representations is investigated by quantum Monte Carlo simulations. While the zero-temperature phase boundary agrees qualitatively with the theoretical predictions based on the 1/N expansion, some unexpected features are also observed. For N> or =5 with the fundamental representation, for example, it is suggested that the <span class="hlt">ground</span> <span class="hlt">states</span> possess exact or approximate U(1) degeneracy. In addition, for the representation of Young tableau with more than one column, the <span class="hlt">ground</span> <span class="hlt">state</span> shows no valence-bond-solid order even at N greater than the threshold value.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DMP.D1147E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DMP.D1147E"><span>Toward Triplet <span class="hlt">Ground</span> <span class="hlt">State</span> NaLi Molecules</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ebadi, Sepehr; Jamison, Alan; Rvachov, Timur; Jing, Li; Son, Hyungmok; Jiang, Yijun; Zwierlein, Martin; Ketterle, Wolfgang</p> <p>2016-05-01</p> <p>The NaLi molecule is expected to have a long lifetime in the triplet <span class="hlt">ground-state</span> due to its fermionic nature, large rotational constant, and weak spin-orbit coupling. The triplet state has both electric and magnetic dipole moments, affording unique opportunities in quantum simulation and ultracold chemistry. We have mapped the excited state NaLi triplet potential by means of photoassociation spectroscopy. We report on this and our further progress toward the creation of the triplet <span class="hlt">ground-state</span> molecules using STIRAP. NSF, ARO-MURI, Samsung, NSERC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Nonli..30.3271C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Nonli..30.3271C"><span><span class="hlt">Ground</span> <span class="hlt">state</span> and orbital stability for the NLS equation on a general starlike graph with potentials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cacciapuoti, Claudio; Finco, Domenico; Noja, Diego</p> <p>2017-08-01</p> <p>We consider a nonlinear Schrödinger equation (NLS) posed on a graph (or network) composed of a generic compact part to which a finite number of half-lines are attached. We call this structure a starlike graph. At the vertices of the graph interactions of δ-type can be present and an overall external potential is admitted. Under general assumptions on the potential, we prove that the NLS is globally well-posed in the <span class="hlt">energy</span> domain. We are interested in minimizing the <span class="hlt">energy</span> of the system on the manifold of constant mass (L 2-norm). When existing, the minimizer is called <span class="hlt">ground</span> <span class="hlt">state</span> and it is the profile of an orbitally stable standing wave for the NLS evolution. We prove that a <span class="hlt">ground</span> <span class="hlt">state</span> exists for sufficiently small masses whenever the quadratic part of the <span class="hlt">energy</span> admits a simple isolated eigenvalue at the bottom of the spectrum (the linear <span class="hlt">ground</span> <span class="hlt">state</span>). This is a wide generalization of a result previously obtained for a star-graph with a single vertex. The main part of the proof is devoted to prove the concentration compactness principle for starlike structures; this is non trivial due to the lack of translation invariance of the domain. Then we show that a minimizing, bounded, H 1 sequence for the constrained NLS <span class="hlt">energy</span> with external linear potentials is in fact convergent if its mass is small enough. Moreover we show that the <span class="hlt">ground</span> <span class="hlt">state</span> bifurcates from the vanishing solution at the bottom of the linear spectrum. Examples are provided with a discussion of the hypotheses on the linear part.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20640192','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20640192"><span>Cold collisions of <span class="hlt">ground-state</span> calcium atoms in a laser field: A theoretical study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bussery-Honvault, Beatrice; Launay, Jean-Michel; Moszynski, Robert</p> <p>2003-09-01</p> <p>State-of-the-art ab initio techniques have been applied to compute the potential-<span class="hlt">energy</span> curves for the ground X {sup 1}{sigma}{sub g}{sup +} and excited {sup 1}{pi}{sub g}(4s3d) states of the calcium dimer in the Born-Oppenheimer approximation. The weakly bound <span class="hlt">ground</span> <span class="hlt">state</span> was calculated by symmetry-adapted perturbation theory, while the strongly bound excited state was computed using a combination of the linear-response theory within the coupled-cluster singles and doubles framework for the core-valence electronic correlation and of the full configuration interaction for the valence-valence correlation. The <span class="hlt">ground-state</span> potential has been corrected by considering the relativistic terms resulting from the first-order many-electron Breit theory, and the retardation corrections. The magnetic electronic transition dipole moment governing the {sup 1}{pi}{sub g}(leftarrow){sup 1}{sigma}{sub g}{sup +} transitions has been obtained as the first residue of the polarization propagator computed with the coupled-cluster method restricted to single and double excitations. The computed <span class="hlt">energies</span> and transition moments have been analytically fitted and used in the dynamical calculations of the rovibrational <span class="hlt">energy</span> levels, <span class="hlt">ground-state</span> scattering length, photoassociation intensities at ultralow temperatures, and spontaneous emission coefficients from the {sup 1}{pi}{sub g}(4s3d) to the X {sup 1}{sigma}{sub g}{sup +} state. The spectroscopic constants of the theoretical <span class="hlt">ground-state</span> potential are in a good agreement with the experimental values derived from the Fourier-transform spectra [O. Allard et al., Eur. Phys. J. D (to be published)]. The theoretical s-wave scattering length for the <span class="hlt">ground</span> <span class="hlt">state</span> is a=44 bohrs, suggesting that it should be possible to obtain a stable Bose-Einstein condensate of calcium atoms. Finally, the computed photoassociation intensities and spontaneous emission coefficients suggest that it should be possible to obtain cold calcium molecules by</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009APS..DMP.M1019G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009APS..DMP.M1019G"><span><span class="hlt">Ground</span> <span class="hlt">state</span> and resonant states of helium in exponential cosine screened Coulomb potential</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghoshal, Arijit; Ho, Y. K.</p> <p>2009-05-01</p> <p>We have investigated the <span class="hlt">ground</span> <span class="hlt">state</span> and a resonance state of normal helium atom in exponential cosine screened Coulomb potential (ECSCP) with screening parameterλ: V(r),,,1r,^-λr(λr) (in a.u.), where r denotes the inter-particle distance. Within the framework of Ritz's variational principle and making use of a highly correlated wave function, we have determined the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energies</span> and wave functions of the helium atom for different values of the screening parameterλ. Furthermore, we have shown that the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span> of helium for a particular value of λ does converge with increasing number of terms in the wave function. In addition, using the stabilization method, we have investigated the doubly excited 2s^2 ^1S^e resonance state in helium with ECSCP. Resonance <span class="hlt">energy</span> and width for various λ values are calculated. Our present work will play a useful role in the investigations of atomic structures in quantum plasmas [1]. [1]. P.K. Shukla and B. Eliasson, Phys. Lett. A 372, 2899 (2008).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JMoSp.239...71Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JMoSp.239...71Y"><span>Ab initio dipole moment and theoretical rovibrational intensities in the electronic <span class="hlt">ground</span> <span class="hlt">state</span> of PH 3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yurchenko, Sergei N.; Carvajal, Miguel; Thiel, Walter; Jensen, Per</p> <p>2006-09-01</p> <p>We report a six-dimensional CCSD(T)/aug-cc-pVTZ dipole moment surface for the electronic <span class="hlt">ground</span> <span class="hlt">state</span> of PH 3 computed ab initio on a large grid of 10 080 molecular geometries. Parameterized, analytical functions are fitted through the ab initio data, and the resulting dipole moment functions are used, together with a potential <span class="hlt">energy</span> function determined by refining an existing ab initio surface in fittings to experimental wavenumber data, for simulating absorption spectra of the first three polyads of PH 3, i.e., ( ν2, ν4), ( ν1, ν3, 2 ν2, 2 ν4, ν2 + ν4), and ( ν1 + ν2, ν3 + ν2, ν1 + ν4, ν3 + ν4, 2 ν2 + ν4, ν2 + 2 ν4, 3 ν2, 3 ν4). The resulting theoretical transition moments show excellent agreement with experiment. A line-by-line comparison of the simulated intensities of the ν2/ ν4 <span class="hlt">band</span> system with 955 experimental intensity values reported by Brown et al. [L.R. Brown, R.L. Sams, I. Kleiner, C. Cottaz, L. Sagui, J. Mol. Spectrosc. 215 (2002) 178-203] gives an average absolute percentage deviation of 8.7% (and a root-mean-square deviation of 0.94 cm -1 for the transition wavenumbers). This is very remarkable since the calculations rely entirely on ab initio dipole moment surfaces and do not involve any adjustment of these surfaces to reproduce the experimental intensities. Finally, we predict the line strengths for transitions between so-called cluster levels (near-degenerate levels formed at high rotational excitation) for J up to 60.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1249339','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1249339"><span>Stabilities and defect-mediated lithium-ion conduction in a <span class="hlt">ground</span> <span class="hlt">state</span> cubic Li<sub>3</sub> N structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nguyen, Manh Cuong; Hoang, Khang; Wang, Cai-Zhuang; Ho, Kai-Ming</p> <p>2016-01-07</p> <p>A stable <span class="hlt">ground</span> <span class="hlt">state</span> structure with cubic symmetry of Li<sub>3</sub>N (c-Li<sub>3</sub>N) is found by ab initio initially symmetric random-generated crystal structure search method. Gibbs free <span class="hlt">energy</span>, calculated within quasi-harmonic approximation, shows that c-Li<sub>3</sub>N is the <span class="hlt">ground</span> <span class="hlt">state</span> structure for a wide range of temperature. The c-Li<sub>3</sub>N structure has a negative thermal expansion coefficient at temperatures lower than room temperature, due mainly to two transverse acoustic phonon modes. This c-Li<sub>3</sub>N phase is a semiconductor with an indirect <span class="hlt">band</span> gap of 1.90 eV within hybrid density functional calculation. We also investigate the migration and energetics of native point defects in c-Li<sub>3</sub>N, including lithium and nitrogen vacancies, interstitials, and anti-site defects. Lithium interstitials are found to have a very low migration barrier (~0.12 eV) and the lowest formation <span class="hlt">energy</span> among all possible defects. Thus, the ionic conduction in c-Li<sub>3</sub>N is expected to occur via an interstitial mechanism, in contrast to that in the well-known α-Li<sub>3</sub>N phase which occurs via a vacancy mechanism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24341283','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24341283"><span><span class="hlt">Ground-state</span> kinetics of bistable redox-active donor-acceptor mechanically interlocked molecules.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fahrenbach, Albert C; Bruns, Carson J; Li, Hao; Trabolsi, Ali; Coskun, Ali; Stoddart, J Fraser</p> <p>2014-02-18</p> <p> (i) <span class="hlt">ground-state</span> effects, the <span class="hlt">energy</span> required to breakup the noncovalent bonding interactions that stabilize either the GSCC or MSCC, (ii) spacer effects, where the structures overcome additional barriers, either steric or electrostatic or both, en route from one co-conformation to the other, and (iii) the physical environment of the bistable MIMs. By managing all three of these effects, chemists can vary these rate constants over many orders of magnitude. We also discuss progress toward achieving mechanostereoselective motion, a key principle in the design and realization of artificial molecular machines capable of doing work at the molecular level, by the strategic implementation of free <span class="hlt">energy</span> barriers to intramolecular motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPSJ...85h4708K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPSJ...85h4708K"><span>First-Principles Momentum Dependent Local Ansatz Approach to the <span class="hlt">Ground-State</span> Properties of Iron-Group Transition Metals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kakehashi, Yoshiro; Chandra, Sumal</p> <p>2016-08-01</p> <p>The <span class="hlt">ground-state</span> properties of iron-group transition metals from Sc to Cu have been investigated on the basis of the first-principles momentum dependent local ansatz (MLA) theory. Correlation <span class="hlt">energy</span> gain is found to show large values for Mn and Fe: 0.090 Ry (Mn) and 0.094 Ry (Fe). The Hund-rule coupling <span class="hlt">energies</span> are found to be 3000 K (Fe), 1400 K (Co), and 300 K (Ni). It is suggested that these values can resolve the inconsistency in magnetic <span class="hlt">energy</span> between the density functional theory and the first-principles dynamical coherent potential approximation theory at finite temperatures. Charge fluctuations are shown to be suppressed by the intra-orbital correlations and inter-orbital charge-charge correlations, so that they show nearly constant values from V to Fe: 1.57 (V and Cr), 1.52 (Mn), and 1.44 (Fe), which are roughly twice as large as those obtained by the d <span class="hlt">band</span> model. The amplitudes of local moments are enhanced by the intra-orbital and inter-orbital spin-spin correlations and show large values for Mn and Fe: 2.87 (Mn) and 2.58 (Fe). These values are in good agreement with the experimental values estimated from the effective Bohr magneton number and the inner core photoemission data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PhLA..317...14C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PhLA..317...14C"><span>Quantum mechanical <span class="hlt">ground</span> <span class="hlt">state</span> of hydrogen obtained from classical electrodynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cole, Daniel C.; Zou, Yi</p> <p>2003-10-01</p> <p>The behavior of a classical charged point particle under the influence of only a Coulombic binding potential and classical electromagnetic zero-point radiation, is shown to agree closely with the probability density distribution of Schrödinger's wave equation for the <span class="hlt">ground</span> <span class="hlt">state</span> of hydrogen. These results again raise the possibility that the main tenets of stochastic electrodynamics (SED) are correct.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21294458','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21294458"><span><span class="hlt">Ground</span> <span class="hlt">states</span> of the massless Derezinski-Gerard model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ohkubo, Atsushi</p> <p>2009-11-15</p> <p>We consider the massless Derezinski-Gerard model introduced by Derezinski and Gerard in 1999. We give a sufficient condition for the existence of a <span class="hlt">ground</span> <span class="hlt">state</span> of the massless Derezinski-Gerard model without the assumption that the Hamiltonian of particles has compact resolvent.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28432287','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28432287"><span>Advantages of Unfair Quantum <span class="hlt">Ground-State</span> Sampling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Brian Hu; Wagenbreth, Gene; Martin-Mayor, Victor; Hen, Itay</p> <p>2017-04-21</p> <p>The debate around the potential superiority of quantum annealers over their classical counterparts has been ongoing since the inception of the field. Recent technological breakthroughs, which have led to the manufacture of experimental prototypes of quantum annealing optimizers with sizes approaching the practical regime, have reignited this discussion. However, the demonstration of quantum annealing speedups remains to this day an elusive albeit coveted goal. We examine the power of quantum annealers to provide a different type of quantum enhancement of practical relevance, namely, their ability to serve as useful samplers from the <span class="hlt">ground-state</span> manifolds of combinatorial optimization problems. We study, both numerically by simulating stoquastic and non-stoquastic quantum annealing processes, and experimentally, using a prototypical quantum annealing processor, the ability of quantum annealers to sample the <span class="hlt">ground-states</span> of spin glasses differently than thermal samplers. We demonstrate that (i) quantum annealers sample the <span class="hlt">ground-state</span> manifolds of spin glasses very differently than thermal optimizers (ii) the nature of the quantum fluctuations driving the annealing process has a decisive effect on the final distribution, and (iii) the experimental quantum annealer samples <span class="hlt">ground-state</span> manifolds significantly differently than thermal and ideal quantum annealers. We illustrate how quantum annealers may serve as powerful tools when complementing standard sampling algorithms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/369684','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/369684"><span>Tuning <span class="hlt">ground</span> <span class="hlt">states</span> and excitations in complex electronic materials</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bishop, A.R.</p> <p>1996-09-01</p> <p>Modern electronic materials are characterized by a great variety of broken-symmetry <span class="hlt">ground</span> <span class="hlt">states</span> and excitations. Their control requires understanding and tuning underlying driving forces of spin-charge-lattice coupling, critical to macroscopic properties and applications. We report representative model calculations which demonstrate some of the richness of the phenomena and the challenges for successful microscopic modeling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EL....11448001S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EL....11448001S"><span><span class="hlt">Energy</span> <span class="hlt">band</span> gaps in graphene nanoribbons with corners</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Szczȩśniak, Dominik; Durajski, Artur P.; Khater, Antoine; Ghader, Doried</p> <p>2016-05-01</p> <p>In the present paper, we study the relation between the <span class="hlt">band</span> gap size and the corner-corner length in representative chevron-shaped graphene nanoribbons (CGNRs) with 120° and 150° corner edges. The direct physical insight into the electronic properties of CGNRs is provided within the tight-binding model with phenomenological edge parameters, developed against recent first-principle results. We show that the analyzed CGNRs exhibit inverse relation between their <span class="hlt">band</span> gaps and corner-corner lengths, and that they do not present a metal-insulator transition when the chemical edge modifications are introduced. Our results also suggest that the <span class="hlt">band</span> gap width for the CGNRs is predominantly governed by the armchair edge effects, and is tunable through edge modifications with foreign atoms dressing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvC..91d1304R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvC..91d1304R"><span><span class="hlt">Ground-state</span> electromagnetic moments of calcium isotopes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ruiz, R. F. Garcia; Bissell, M. L.; Blaum, K.; Frömmgen, N.; Hammen, M.; Holt, J. D.; Kowalska, M.; Kreim, K.; Menéndez, J.; Neugart, R.; Neyens, G.; Nörtershäuser, W.; Nowacki, F.; Papuga, J.; Poves, A.; Schwenk, A.; Simonis, J.; Yordanov, D. T.</p> <p>2015-04-01</p> <p>Background: The neutron-rich calcium isotopes have gained particular interest as evidence of closed-shell structures has recently been found in two exotic nuclei, at N =32 and N =34 . Additionally, the study of such neutron-rich systems has revealed new aspects of nuclear forces, in particular regarding the role of three-nucleon forces. Purpose: We study the electromagnetic properties of Ca isotopes around the neutron number N =32 . Methods: High-resolution bunched-beam collinear laser spectroscopy was used to measure the optical hyperfine spectra of the Ca-5143 isotopes. Results: The <span class="hlt">ground-state</span> magnetic moments of Ca,5149 and quadrupole moments of <mml:mmultiscripts>Ca 47 ,49 ,51 </mml:mmultiscripts> were measured for the first time, and the 51Ca <span class="hlt">ground-state</span> spin I = 3 /2 was determined in a model-independent way. Our experimental results are compared with state-of-the-art shell-model calculations using both phenomenological interactions and microscopic interactions derived from chiral effective field theory. Conclusions: The results for the <span class="hlt">ground-state</span> moments of neutron-rich isotopes are in excellent agreement with predictions of interactions derived from chiral effective field theory including three-nucleon forces. Lighter isotopes illustrate the presence of particle-hole excitations of the 40Ca core in their <span class="hlt">ground</span> <span class="hlt">state</span>. Our results provide a critical test of modern nuclear theories, and give direct answer to the evolution of <span class="hlt">ground-state</span> electromagnetic properties in the Ca isotopic chain across three doubly closed-shell configurations at N =20 , 28, 32 of this unique system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatSR...5E7821R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatSR...5E7821R"><span>Rayleigh approximation to <span class="hlt">ground</span> <span class="hlt">state</span> of the Bose and Coulomb glasses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ryan, S. D.; Mityushev, V.; Vinokur, V. M.; Berlyand, L.</p> <p>2015-01-01</p> <p>Glasses are rigid systems in which competing interactions prevent simultaneous minimization of local <span class="hlt">energies</span>. This leads to frustration and highly degenerate <span class="hlt">ground</span> <span class="hlt">states</span> the nature and properties of which are still far from being thoroughly understood. We report an analytical approach based on the method of functional equations that allows us to construct the Rayleigh approximation to the <span class="hlt">ground</span> <span class="hlt">state</span> of a two-dimensional (2D) random Coulomb system with logarithmic interactions. We realize a model for 2D Coulomb glass as a cylindrical type II superconductor containing randomly located columnar defects (CD) which trap superconducting vortices induced by applied magnetic field. Our findings break ground for analytical studies of glassy systems, marking an important step towards understanding their properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1194163-rayleigh-approximation-ground-state-bose-coulomb-glasses','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1194163-rayleigh-approximation-ground-state-bose-coulomb-glasses"><span>Rayleigh approximation to <span class="hlt">ground</span> <span class="hlt">state</span> of the Bose and Coulomb glasses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Ryan, S. D.; Mityushev, V.; Vinokur, V. M.; ...</p> <p>2015-01-16</p> <p>Glasses are rigid systems in which competing interactions prevent simultaneous minimization of local <span class="hlt">energies</span>. This leads to frustration and highly degenerate <span class="hlt">ground</span> <span class="hlt">states</span> the nature and properties of which are still far from being thoroughly understood. We report an analytical approach based on the method of functional equations that allows us to construct the Rayleigh approximation to the <span class="hlt">ground</span> <span class="hlt">state</span> of a two-dimensional (2D) random Coulomb system with logarithmic interactions. We realize a model for 2D Coulomb glass as a cylindrical type II superconductor containing randomly located columnar defects (CD) which trap superconducting vortices induced by applied magnetic field. Ourmore » findings break ground for analytical studies of glassy systems, marking an important step towards understanding their properties.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvL.117s7202S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvL.117s7202S"><span><span class="hlt">Ground-State</span> Cooling of a Mechanical Oscillator by Interference in Andreev Reflection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stadler, P.; Belzig, W.; Rastelli, G.</p> <p>2016-11-01</p> <p>We study the <span class="hlt">ground-state</span> cooling of a mechanical oscillator linearly coupled to the charge of a quantum dot inserted between a normal metal and a superconducting contact. Such a system can be realized, e.g., by a suspended carbon nanotube quantum dot with a capacitive coupling to a gate contact. Focusing on the subgap transport regime, we analyze the inelastic Andreev reflections which drive the resonator to a nonequilibrium state. For small coupling, we obtain that vibration-assisted reflections can occur through two distinct interference paths. The interference determines the ratio between the rates of absorption and emission of vibrational <span class="hlt">energy</span> quanta. We show that <span class="hlt">ground-state</span> cooling of the mechanical oscillator can be achieved for many of the oscillator's modes simultaneously or for single modes selectively, depending on the experimentally tunable coupling to the superconductor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27858451','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27858451"><span><span class="hlt">Ground-State</span> Cooling of a Mechanical Oscillator by Interference in Andreev Reflection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stadler, P; Belzig, W; Rastelli, G</p> <p>2016-11-04</p> <p>We study the <span class="hlt">ground-state</span> cooling of a mechanical oscillator linearly coupled to the charge of a quantum dot inserted between a normal metal and a superconducting contact. Such a system can be realized, e.g., by a suspended carbon nanotube quantum dot with a capacitive coupling to a gate contact. Focusing on the subgap transport regime, we analyze the inelastic Andreev reflections which drive the resonator to a nonequilibrium state. For small coupling, we obtain that vibration-assisted reflections can occur through two distinct interference paths. The interference determines the ratio between the rates of absorption and emission of vibrational <span class="hlt">energy</span> quanta. We show that <span class="hlt">ground-state</span> cooling of the mechanical oscillator can be achieved for many of the oscillator's modes simultaneously or for single modes selectively, depending on the experimentally tunable coupling to the superconductor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvA..95d3625T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvA..95d3625T"><span>Strong-coupling corrections to <span class="hlt">ground-state</span> properties of a superfluid Fermi gas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tajima, Hiroyuki; van Wyk, Pieter; Hanai, Ryo; Kagamihara, Daichi; Inotani, Daisuke; Horikoshi, Munekazu; Ohashi, Yoji</p> <p>2017-04-01</p> <p>We theoretically present an economical and convenient way to study <span class="hlt">ground-state</span> properties of a strongly interacting superfluid Fermi gas. Our strategy is that complicated strong-coupling calculations are used only to evaluate quantum fluctuation corrections to the chemical potential μ . Then, without any further strong-coupling calculations, we calculate the compressibility, sound velocity, internal <span class="hlt">energy</span>, pressure, and Tan's contact, from the calculated μ without loss of accuracy, by using exact thermodynamic identities. Using a recent precise measurement of μ in a superfluid 6Li Fermi gas, we show that an extended T -matrix approximation (ETMA) is suitable for our purpose, especially in the BCS-unitary regime, where our results indicate that many-body corrections are dominated by superfluid fluctuations. Since precise determinations of physical quantities are not always easy in cold Fermi gas physics, our approach would greatly reduce experimental and theoretical efforts toward the understanding of <span class="hlt">ground-state</span> properties of this strongly interacting Fermi system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvL.114t5302P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvL.114t5302P"><span>Ultracold Dipolar Gas of Fermionic 23Na 40K Molecules in Their Absolute <span class="hlt">Ground</span> <span class="hlt">State</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Jee Woo; Will, Sebastian A.; Zwierlein, Martin W.</p> <p>2015-05-01</p> <p>We report on the creation of an ultracold dipolar gas of fermionic 23Na 40K molecules in their absolute rovibrational and hyperfine <span class="hlt">ground</span> <span class="hlt">state</span>. Starting from weakly bound Feshbach molecules, we demonstrate hyperfine resolved two-photon transfer into the singlet X 1Σ+ |v =0 ,J =0 ⟩ <span class="hlt">ground</span> <span class="hlt">state</span>, coherently bridging a binding <span class="hlt">energy</span> difference of 0.65 eV via stimulated rapid adiabatic passage. The spin-polarized, nearly quantum degenerate molecular gas displays a lifetime longer than 2.5 s, highlighting NaK's stability against two-body chemical reactions. A homogeneous electric field is applied to induce a dipole moment of up to 0.8 D. With these advances, the exploration of many-body physics with strongly dipolar Fermi gases of 23Na 40K molecules is within experimental reach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JPSJ...83c4707H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPSJ...83c4707H"><span><span class="hlt">Ground-State</span> Phase Diagram of S = 2 Heisenberg Chains with Alternating Single-Site Anisotropy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hida, Kazuo</p> <p>2014-03-01</p> <p>The <span class="hlt">ground-state</span> phase diagram of S = 2 antiferromagnetic Heisenberg chains with coexisting uniform and alternating single-site anisotropies is investigated by the numerical exact diagonalization and density matrix renormalization group methods. We find the Haldane, large-D, Néel, period-doubled Néel, gapless spin fluid, quantized and partial ferrimagnetic phases. The Haldane phase is limited to the close neighborhood of the isotropic point. Within numerical accuracy, the transition from the gapless spin-fluid phase to the period-doubled Néel phase is a direct transition. Nevertheless, the presence of a narrow spin-gap phase between these two phases is suggested on the basis of the low-<span class="hlt">energy</span> effective theory. The ferrimagnetic <span class="hlt">ground</span> <span class="hlt">state</span> is present in a wide parameter range. This suggests the realization of magnetized single-chain magnets with a uniform spin magnitude by controlling the environment of each magnetic ion without introducing ferromagnetic interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017isms.confETC08Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017isms.confETC08Z"><span>Germanium Dicarbide: Evidence for a T-Shaped <span class="hlt">Ground</span> <span class="hlt">State</span> Structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zingsheim, Oliver; Martin-Drumel, Marie-Aline; Thorwirth, Sven; Schlemmer, Stephan; Gottlieb, Carl A.; Gauss, Jürgen; McCarthy, Michael C.</p> <p>2017-06-01</p> <p>The preferred equilibrium structure of germanium dicarbide (GeC_2) has been an open question for decades: while high-level quantum chemical calculations predict an L-shaped <span class="hlt">ground</span> <span class="hlt">state</span> structure, the very flat potential <span class="hlt">energy</span> surface of the species prevents a T-shaped structure from being entirely ruled out^1. By recording for the first time the rotational spectrum of GeC_2 using sensitive microwave and millimeter techniques, we establish that the molecule adopts a vibrationally-averaged T-shaped structure in the <span class="hlt">ground</span> <span class="hlt">state</span>. From isotopic substitution of 14 isotopologues, a precise r_0 structure has been derived. This structural work should serve as an important benchmark for future calculations. ^1 Sari et al., J. Chem. Phys. 117 10008 (2002)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ChPhB..25c3204Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ChPhB..25c3204Y"><span>Electron excitation from <span class="hlt">ground</span> <span class="hlt">state</span> to first excited state: Bohmian mechanics method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Song; Shuang, Zhao; Fu-Ming, Guo; Yu-Jun, Yang; Su-Yu, Li</p> <p>2016-03-01</p> <p>The excitation process of electrons from the <span class="hlt">ground</span> <span class="hlt">state</span> to the first excited state via the resonant laser pulse is investigated by the Bohmian mechanics method. It is found that the Bohmian particles far away from the nucleus are easier to be excited and are excited firstly, while the Bohmian particles in the <span class="hlt">ground</span> <span class="hlt">state</span> is subject to a strong quantum force at a certain moment, being excited to the first excited state instantaneously. A detailed analysis for one of the trajectories is made, and finally we present the space and <span class="hlt">energy</span> distribution of 2000 Bohmian particles at several typical instants and analyze their dynamical process at these moments. Project supported by the Doctoral Research Start-up Funding of Northeast Dianli University, China (Grant No. BSJXM-201332), the National Natural Science Foundation of China (Grant Nos. 11547114, 11534004, 11474129, 11274141, 11447192, and 11304116), and the Graduate Innovation Fund of Jilin University, China (Grant No. 2015091).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JDE...261.5180A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JDE...261.5180A"><span><span class="hlt">Ground</span> <span class="hlt">states</span> for irregular and indefinite superlinear Schrödinger equations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ackermann, Nils; Chagoya, Julián</p> <p>2016-11-01</p> <p>We consider the existence of a <span class="hlt">ground</span> <span class="hlt">state</span> for the subcritical stationary semilinear Schrödinger equation - Δu + u = a (x) | u| p - 2 u in H1, where a ∈L∞ (RN) may change sign. Our focus is on the case where loss of compactness occurs at the <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span>. By providing a new variant of the Splitting Lemma we do not need to assume the existence of a limit problem at infinity, be it in the form of a pointwise limit for a as | x | → ∞ or of asymptotic periodicity. That is, our problem may be irregular at infinity. In addition, we allow a to change sign near infinity, a case that has never been treated before.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvL.113y5301M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvL.113y5301M"><span>Creation of Ultracold 87Rb 133Cs Molecules in the Rovibrational <span class="hlt">Ground</span> <span class="hlt">State</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Molony, Peter K.; Gregory, Philip D.; Ji, Zhonghua; Lu, Bo; Köppinger, Michael P.; Le Sueur, C. Ruth; Blackley, Caroline L.; Hutson, Jeremy M.; Cornish, Simon L.</p> <p>2014-12-01</p> <p>We report the creation of a sample of over 1000 ultracold 87Rb 133Cs molecules in the lowest rovibrational <span class="hlt">ground</span> <span class="hlt">state</span>, from an atomic mixture of 87Rb and 133Cs, by magnetoassociation on an interspecies Feshbach resonance followed by stimulated Raman adiabatic passage (STIRAP). We measure the binding <span class="hlt">energy</span> of the RbCs molecule to be h c ×3811.576 (1 ) cm-1 and the |v''=0 ,J''=0 ⟩ to |v''=0 ,J''=2 ⟩ splitting to be h ×2940.09 (6 ) MHz . Stark spectroscopy of the rovibrational <span class="hlt">ground</span> <span class="hlt">state</span> yields an electric dipole moment of 1.225(3)(8) D, where the values in parentheses are the statistical and systematic uncertainties, respectively. We can access a space-fixed dipole moment of 0.355(2)(4) D, which is substantially higher than in previous work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25554891','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25554891"><span>Creation of ultracold ^{87}Rb^{133}Cs molecules in the rovibrational <span class="hlt">ground</span> <span class="hlt">state</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Molony, Peter K; Gregory, Philip D; Ji, Zhonghua; Lu, Bo; Köppinger, Michael P; Le Sueur, C Ruth; Blackley, Caroline L; Hutson, Jeremy M; Cornish, Simon L</p> <p>2014-12-19</p> <p>We report the creation of a sample of over 1000 ultracold ^{87}Rb^{133}Cs molecules in the lowest rovibrational <span class="hlt">ground</span> <span class="hlt">state</span>, from an atomic mixture of ^{87}Rb and ^{133}Cs, by magnetoassociation on an interspecies Feshbach resonance followed by stimulated Raman adiabatic passage (STIRAP). We measure the binding <span class="hlt">energy</span> of the RbCs molecule to be hc×3811.576(1)  cm^{-1} and the |v^{''}=0,J^{''}=0⟩ to |v^{''}=0,J^{''}=2⟩ splitting to be h×2940.09(6)  MHz. Stark spectroscopy of the rovibrational <span class="hlt">ground</span> <span class="hlt">state</span> yields an electric dipole moment of 1.225(3)(8) D, where the values in parentheses are the statistical and systematic uncertainties, respectively. We can access a space-fixed dipole moment of 0.355(2)(4) D, which is substantially higher than in previous work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26047239','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26047239"><span>Ultracold Dipolar Gas of Fermionic 23Na40 K Molecules in Their Absolute <span class="hlt">Ground</span> <span class="hlt">State</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Jee Woo; Will, Sebastian A; Zwierlein, Martin W</p> <p>2015-05-22</p> <p>We report on the creation of an ultracold dipolar gas of fermionic 23Na40 K molecules in their absolute rovibrational and hyperfine <span class="hlt">ground</span> <span class="hlt">state</span>. Starting from weakly bound Feshbach molecules, we demonstrate hyperfine resolved two-photon transfer into the singlet X 1Σ+|v=0,J=0⟩ <span class="hlt">ground</span> <span class="hlt">state</span>, coherently bridging a binding <span class="hlt">energy</span> difference of 0.65 eV via stimulated rapid adiabatic passage. The spin-polarized, nearly quantum degenerate molecular gas displays a lifetime longer than 2.5 s, highlighting NaK's stability against two-body chemical reactions. A homogeneous electric field is applied to induce a dipole moment of up to 0.8 D. With these advances, the exploration of many-body physics with strongly dipolar Fermi gases of 23Na40K molecules is within experimental reach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1194163','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1194163"><span>Rayleigh approximation to <span class="hlt">ground</span> <span class="hlt">state</span> of the Bose and Coulomb glasses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ryan, S. D.; Mityushev, V.; Vinokur, V. M.; Berlyand, L.</p> <p>2015-01-16</p> <p>Glasses are rigid systems in which competing interactions prevent simultaneous minimization of local <span class="hlt">energies</span>. This leads to frustration and highly degenerate <span class="hlt">ground</span> <span class="hlt">states</span> the nature and properties of which are still far from being thoroughly understood. We report an analytical approach based on the method of functional equations that allows us to construct the Rayleigh approximation to the <span class="hlt">ground</span> <span class="hlt">state</span> of a two-dimensional (2D) random Coulomb system with logarithmic interactions. We realize a model for 2D Coulomb glass as a cylindrical type II superconductor containing randomly located columnar defects (CD) which trap superconducting vortices induced by applied magnetic field. Our findings break ground for analytical studies of glassy systems, marking an important step towards understanding their properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20639799','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20639799"><span><span class="hlt">Ground-state</span> properties of trapped Bose-Fermi mixtures: Role of exchange correlation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Albus, Alexander P.; Wilkens, Martin; Illuminati, Fabrizio</p> <p>2003-06-01</p> <p>We introduce density-functional theory for inhomogeneous Bose-Fermi mixtures, derive the associated Kohn-Sham equations, and determine the exchange-correlation <span class="hlt">energy</span> in local-density approximation. We solve numerically the Kohn-Sham system, and determine the boson and fermion density distributions and the <span class="hlt">ground-state</span> <span class="hlt">energy</span> of a trapped, dilute mixture beyond mean-field approximation. The importance of the corrections due to exchange correlation is discussed by a comparison with current experiments; in particular, we investigate the effect of the repulsive potential-<span class="hlt">energy</span> contribution due to exchange correlation on the stability of the mixture against collapse.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96i4409V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96i4409V"><span>Induced quadrupolar singlet <span class="hlt">ground</span> <span class="hlt">state</span> of praseodymium in a modulated pyrochlore</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Duijn, J.; Kim, K. H.; Hur, N.; Ruiz-Bustos, R.; Adroja, D. T.; Bridges, F.; Daoud-Aladine, A.; Fernandez-Alonso, F.; Wen, J. J.; Kearney, V.; Huang, Q. Z.; Cheong, S.-W.; Perring, T. G.; Broholm, C.</p> <p>2017-09-01</p> <p>The complex structure and magnetism of Pr2 -xBixRu2O7 was investigated by neutron scattering and extended x-ray absorption fine structure. Pr has an approximate doublet <span class="hlt">ground</span> <span class="hlt">state</span> and the first excited state is a singlet. While the B -site (Ru) is well ordered throughout, this is not the case for the A -site (Pr/Bi). A broadened distribution for the Pr-O2 bond length at low temperature indicates the Pr environment varies from site to site even for x =0 . The environment about the Bi site is highly disordered ostensibly due to the 6 s lone pairs on Bi3 +. Correspondingly, we find that the non-Kramers doublet <span class="hlt">ground-state</span> degeneracy, otherwise anticipated for Pr in the pyrochlore structure, is lifted so as to produce a quadrupolar singlet <span class="hlt">ground</span> <span class="hlt">state</span> with a spatially varying <span class="hlt">energy</span> gap. For x =0 , below TN, the Ru sublattice orders antiferromagnetically, with propagation vector k =(0 ,0 ,0 ) as for Y2Ru2O7 . No ordering associated with the Pr sublattice is observed down to 100 mK. The low-<span class="hlt">energy</span> magnetic response of Pr2 -xBixRu2O7 features a broad spectrum of magnetic excitations associated with inhomogeneous splitting of the Pr quasidoublet <span class="hlt">ground</span> <span class="hlt">state</span>. For x =0 (x =0.97 ), the spectrum is temperature dependent (independent). It appears disorder associated with Bi alloying enhances the inhomogeneous Pr crystal-field level splitting so that intersite interactions become irrelevant for x =0.97 . The structural complexity for the A -site may be reflected in the hysteretic uniform magnetization of B -site ruthenium in the Néel phase.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992PhRvA..46.5459F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992PhRvA..46.5459F"><span>Single-configuration descriptions of atomic ground and excited states - <span class="hlt">Ground</span> <span class="hlt">states</span> of He, Li, and Be</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fletcher, Graham D.; Doggett, Graham; Howard, Alan S.</p> <p>1992-11-01</p> <p>A first-derivative variational principle is applied to the optimization of a single-configuration spin-coupled wave function to determine the <span class="hlt">ground</span> <span class="hlt">states</span> of some atoms. An orbital is chosen and optimized, and an expansion is taken for the orbital over a set of primitive atomic orbitals. Expected values of spin-free and -dependent operators are developed, and optimum wave-function parameters are determined for evaluating radial moments and radial density functions from spin or spinless one-electron density functions. The method is applied to the <span class="hlt">ground-state</span> properties of He, Li, and Be by means of even-tempered and Clementi-Roetti basis sets. <span class="hlt">Energy</span> profiles are determined for spin-coupled and full configuration-interaction computations. The <span class="hlt">ground</span> <span class="hlt">states</span> of He, Li, and Be are found to have <span class="hlt">energy</span> profiles with a global minimum and at least on local minimum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18233880','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18233880"><span>Stability of the high-density ferromagnetic <span class="hlt">ground</span> <span class="hlt">state</span> of a chargeless, magnetic-dipolar, quantum Fermi liquid.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mahanti, S D; Jha, Sudhanshu S</p> <p>2007-12-01</p> <p>We obtain the best upper bound for the <span class="hlt">ground-state</span> <span class="hlt">energy</span> of a system of chargeless fermions of mass m, spin s=1/2 , and magnetic moment mus[over ] as a function of its density in the fully spin-polarized Hartree-Fock determinantal state, specified by a prolate spheroidal plane-wave single-particle occupation function n_(k[over ]) , by minimizing the total <span class="hlt">energy</span> E at each density with respect to the variational spheroidal deformation parameter beta(2),0< or =beta(2)< or =1 . We find that at high densities, this spheroidal ferromagnetic state is the most likely <span class="hlt">ground</span> <span class="hlt">state</span> of the system, but it is still unstable towards the infinite-density collapse. This optimized ferromagnetic state is shown to be a stable <span class="hlt">ground</span> <span class="hlt">state</span> of the dipolar system at high densities, if one has an additional repulsive short-range hardcore interaction of sufficient strength and nonvanishing range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..MARP36012E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..MARP36012E"><span>Accessing high <span class="hlt">energy</span> sub-<span class="hlt">bands</span> in bilayer graphene - a transport study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Efetov, Dmitri K.; Maher, Patrick; Glinskis, Simas; Kim, Philip</p> <p>2011-03-01</p> <p>In contrast to single layer graphene sheets with its two distinct valence and conduction <span class="hlt">bands</span> merging at the Dirac Point, multilayer graphene sheets are known to have additional sub-<span class="hlt">bands</span> at higher <span class="hlt">energies</span>. Whereas the low <span class="hlt">energy</span> sub-<span class="hlt">bands</span> in these systems are well studied, the higher <span class="hlt">energy</span> sub-<span class="hlt">bands</span> could so far not be accessed in a transport measurement of graphene samples sitting on typical Si O2 /Si back gates. Employing a poly(ethylene)oxide- CsCl O4 solid polymer electrolyte gate we demonstrate the filling up of the high <span class="hlt">energy</span> sub-<span class="hlt">bands</span> in bilayer graphene samples at carrier densities above ~ 2.7 x 1013 cm-2 . The onset of these sub-<span class="hlt">bands</span> is defined by a slight increase of the resistivity and the onset of Shubnikov de Haas (SdH) oscillations. Measurements of the magneto-resistance, the SdH oscillations and the Hall Effect enable us to deduce the carrier densities and mobilities for both, the high and low <span class="hlt">energy</span> <span class="hlt">bands</span> simultaneously. In addition, we find that the onset <span class="hlt">energy</span> of these sub-<span class="hlt">bands</span> can be tuned by varying the bilayer interlayer asymmetry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT........67Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT........67Z"><span>Production of Ultracold, Absolute Vibrational <span class="hlt">Ground</span> <span class="hlt">State</span> Sodium-Cesium Molecules</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zabawa, Patrick J.</p> <p></p> <p>This dissertation describes a progression of experiments that are based on the association of ultracold (˜250 muK) Na and Cs atoms with laser light. One of the primary goals of the experiment is to form molecules in the absolute vibrational <span class="hlt">ground</span> <span class="hlt">state</span>. The work begins with our attempts to label, with certainty, spectral lines obtained from tuning either the photoassociation (PA formation) and Resonance Enhanced Multi-Photon Ionization (REMPI detection) lasers. To this end, we develop a technique that has heretofore never been used in the ultracold molecule community: pulsed depletion spectroscopy (PDS). Traditionally, depletion spectroscopy involves the use of narrow-linewidth CW lasers. However, the narrow linewidth and limited tuning ranges of diodes used for CW depletion spectroscopy mean that this technique is only helpful if the expected transitions are known to some degree in advance, and even then is primarily useful for determining closely-spaced rotational <span class="hlt">ground</span> <span class="hlt">state</span> populations. In contrast, the broad linewidth and flexible tuning range of a pulsed dye laser makes it suitable for the detection of vibrational progressions, allowing fast determination of <span class="hlt">ground</span> <span class="hlt">state</span> populations even without a priori knowledge of the transitions involved. We also use this technique in our investigation of excited state potential <span class="hlt">energy</span> curves (PECs). We also investigate a range of PA resonances detuned from the Cs D1 and D2 lines. We find and label PA structure associated with at least 6, and possibly all 8 electronic states corresponding to both of the Cs 6P fine structure asymptotes. From the PA and depletion spectra, we obtain information on the PA scattering process and the excited electronic states. Among the PA spectra, we find several channels which directly form vibrational <span class="hlt">ground</span> <span class="hlt">state</span> molecules in the singlet electronic state. Finally, we manipulate the internal states of molecules created with PA using laser light. We use broadband laser sources to pump</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27704234','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27704234"><span>Estimation of <span class="hlt">Ground-State</span> and Singlet Excited-State Dipole Moments of Substituted Schiff Bases Containing Oxazolidin-2-one Moiety through Solvatochromic Methods.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kumari, Rekha; Varghese, Anitha; George, Louis</p> <p>2017-01-01</p> <p>Absorption and fluorescence studies on novel Schiff bases (E)-4-(4-(4-nitro benzylideneamino)benzyl)oxazolidin-2-one (NBOA) and (E)-4-(4-(4-chlorobenzylidene amino)benzyl)oxazolidin-2-one (CBOA) were recorded in a series of twelve solvents upon increasing polarity at room temperature. Large Stokes shift indicates bathochromic fluorescence <span class="hlt">band</span> for both the molecules. The photoluminescence properties of Schiff bases containing electron withdrawing and donating substituents were analyzed. Intramolecular charge transfer behavior can be studied based on the influence of different substituents in Schiff bases. Changes in position and intensity of absorption and fluorescence spectra are responsible for the stabilization of singlet excited-states of Schiff base molecules with different substituents, in polar solvents. This is attributed to the Intramolecular charge transfer (ICT) mechanism. In case of electron donating (-Cl) substituent, ICT contributes largely to positive solvatochromism when compared to electron withdrawing (-NO2) substituent. <span class="hlt">Ground-state</span> and singlet excited-state dipole moments of NBOA and CBOA were calculated experimentally using solvent polarity function approaches given by Lippert-Mataga, Bakhshiev, Kawskii-Chamma-Viallet and Reichardt. Due to considerable π- electron density redistribution, singlet excited-state dipole moment was found to be greater than <span class="hlt">ground-state</span> dipole moment. <span class="hlt">Ground-state</span> dipole moment value which was determined by quantum chemical method was used to estimate excited-state dipole moment using solvatochromic correlations. Kamlet-Abboud-Taft and Catalan multiple linear regression approaches were used to study non-specific solute-solvent interaction and hydrogen bonding interactions in detail. Optimized geometry and HOMO-LUMO <span class="hlt">energies</span> of NBOA and CBOA have been determined by DFT and TD-DFT/PCM (B3LYP/6-311G (d, p)). Mulliken charges and molecular electrostatic potential have also been evaluated from DFT calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhD...50NLT02G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhD...50NLT02G"><span>A novel theoretical model for the temperature dependence of <span class="hlt">band</span> gap <span class="hlt">energy</span> in semiconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geng, Peiji; Li, Weiguo; Zhang, Xianhe; Zhang, Xuyao; Deng, Yong; Kou, Haibo</p> <p>2017-10-01</p> <p>We report a novel theoretical model without any fitting parameters for the temperature dependence of <span class="hlt">band</span> gap <span class="hlt">energy</span> in semiconductors. This model relates the <span class="hlt">band</span> gap <span class="hlt">energy</span> at the elevated temperature to that at the arbitrary reference temperature. As examples, the <span class="hlt">band</span> gap <span class="hlt">energies</span> of Si, Ge, AlN, GaN, InP, InAs, ZnO, ZnS, ZnSe and GaAs at temperatures below 400 K are calculated and are in good agreement with the experimental results. Meanwhile, the <span class="hlt">band</span> gap <span class="hlt">energies</span> at high temperatures (T  >  400 K) are predicted, which are greater than the experimental results, and the reasonable analysis is carried out as well. Under low temperatures, the effect of lattice expansion on the <span class="hlt">band</span> gap <span class="hlt">energy</span> is very small, but it has much influence on the <span class="hlt">band</span> gap <span class="hlt">energy</span> at high temperatures. Therefore, it is necessary to consider the effect of lattice expansion at high temperatures, and the method considering the effect of lattice expansion has also been given. The model has distinct advantages compared with the widely quoted Varshni’s semi-empirical equation from the aspect of modeling, physical meaning and application. The study provides a convenient method to determine the <span class="hlt">band</span> gap <span class="hlt">energy</span> under different temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMoSp.312..110S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMoSp.312..110S"><span>Dunham coefficients for the X1Σ+ <span class="hlt">ground</span> <span class="hlt">state</span> of BH and BD</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shayesteh, Alireza; Ghazizadeh, Ehsan</p> <p>2015-06-01</p> <p>All available spectroscopic data for the X1Σ+, A1Π and B1Σ+ states of BH and BD have been combined in a multi-isotopologue fit to obtain Dunham coefficients for the X1Σ+ <span class="hlt">ground</span> <span class="hlt">state</span>. With no vibration-rotation data available for BD, the only way to determine the v = 1 ← 0 interval in the X1Σ+ <span class="hlt">ground</span> <span class="hlt">state</span> of BD was to use the 1-1 and 1-0 <span class="hlt">bands</span> of the B1Σ+ - X1Σ+ system. An incorrect J assignment was found in the published data of the 1-0 <span class="hlt">band</span> of the B1Σ+ - X1Σ+ system of BD, making them inconsistent with the more accurate data from the A1Π - X1Σ+ system. With the correct J assignment, the v = 1 ← 0 interval in the X1Σ+, A1Π and B1Σ+ states of 11BD were determined to be 1690.773, 1581.095 and 1687.90 cm-1, respectively. The values listed in Huber and Herzberg's book differ from the above values by ∼2B, because they are based on an incorrect J assignment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyB..481..104D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyB..481..104D"><span>Threshold conditions, <span class="hlt">energy</span> spectrum and <span class="hlt">bands</span> generated by locally periodic Dirac comb potentials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dharani, M.; Shastry, C. S.</p> <p>2016-01-01</p> <p>We derive expressions for polynomials governing the threshold conditions for different types of locally periodic Dirac comb potentials comprising of attractive and combination of attractive and repulsive delta potential terms confined symmetrically inside a one dimensional box of fixed length. The roots of these polynomials specify the conditions on the potential parameters in order to generate threshold <span class="hlt">energy</span> bound states. The mathematical and numerical methods used by us were first formulated in our earlier works and it is also very briefly summarized in this paper. We report a number of mathematical results pertaining to the threshold conditions and these are useful in controlling the number of negative <span class="hlt">energy</span> states as desired. We further demonstrate the correlation between the distribution of roots of these polynomials and negative <span class="hlt">energy</span> eigenvalues. Using these results as basis, we investigate the <span class="hlt">energy</span> <span class="hlt">bands</span> in the positive <span class="hlt">energy</span> spectrum for the above specified Dirac comb potentials and also for the corresponding repulsive case. In the case of attractive Dirac comb the base <span class="hlt">energy</span> of the each <span class="hlt">band</span> excluding the first <span class="hlt">band</span> coincides with specific eigenvalue of the confining box whereas in the repulsive case it coincides with the <span class="hlt">band</span> top. We deduce systematic correlation between <span class="hlt">band</span> gaps, <span class="hlt">band</span> spreads and box eigenvalues and explain the physical reason for the vanishing of <span class="hlt">band</span> pattern at higher <span class="hlt">energies</span>. In the case of Dirac comb comprising of orderly arranged attractive and repulsive delta potentials, specific box eigenvalues occur in the middle of each <span class="hlt">band</span> excluding the first <span class="hlt">band</span>. From our study we find that by controlling the number and strength parameters of delta terms in the Dirac comb and the size of confining box it is possible to generate desired types of <span class="hlt">band</span> formations. We believe the results from our systematic analysis are useful and relevant in the study of various one dimensional systems of physical interest in areas like nanoscience.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7149811','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7149811"><span>A <span class="hlt">ground</span> <span class="hlt">state</span> depleted laser in neodymium doped yttrium orthosilicate</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Beach, R.; Albrecht, G.; Solarz, R.; Krupke, W.; Comaskey, B.; Mitchell, S.; Brandle, C.; Berkstresser, G.</p> <p>1990-01-16</p> <p>A <span class="hlt">ground</span> <span class="hlt">state</span> depleted (GSD){sup 1,2} laser has been demonstrated in the form of a Q-switched oscillator operating at 912 nm. Using Nd{sup 3+} as the active ion and Y{sub 2}SiO{sub 5} as the host material, the laser transition is from the lowest lying stark level of the Nd{sup 3t}F{sub 3/2} level to a stark level 355 cm{sup {minus}1} above the lowest lying one in the {sup 4}I{sub 9/2} manifold. The necessity of depleting the ground {sup 4}I{sub 9/2} manifold is evident for this level scheme as transparency requires a 10% inversion. To achieve the high excitation levels required for the efficient operation of this laser, bleach wave pumping using an alexandrite laser at 745 nm has been employed. The existence of a large absorption feature at 810 nm also allows for the possibility of AlGaAs laser diode pumping. Using KNbO{sub 3}, noncritical phase matching is possible at 140{degree}C using d{sub 32} and has been demonstrated. The results of Q-switched laser performance and harmonic generation in KNbO{sub 3} will be presented. Orthosilicate can be grown in large boules of excellent optical quality using a Czochralski technique. Because of the relatively small 912 nm emission cross section of 2-3 {times} 10{sup {minus}20} cm{sup 2} (orientation dependent) fluences of 10-20 J/cm{sup 2} must be circulated in the laser cavity for the efficient extraction of stored <span class="hlt">energy</span>. This necessitates very aggressive laser damage thresholds. Results from the Reptile laser damage facility at Lawrence Livermore National Laboratory (LLNL) will be presented showing Y{sub 2}SiO{sub 5} bulk and AR sol-gel coated surface damage thresholds of greater than 40 J/cm{sup 2} for 10 nsec, 10 Hz, 1.06 {mu} pulses. 16 refs., 18 figs., 6 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28325035','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28325035"><span>Calculation of <span class="hlt">Energy</span> Diagram of Asymmetric Graded-<span class="hlt">Band</span>-Gap Semiconductor Superlattices.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Monastyrskii, Liubomyr S; Sokolovskii, Bogdan S; Alekseichyk, Mariya P</p> <p>2017-12-01</p> <p>The paper theoretically investigates the peculiarities of <span class="hlt">energy</span> diagram of asymmetric graded-<span class="hlt">band</span>-gap superlattices with linear coordinate dependences of <span class="hlt">band</span> gap and electron affinity. For calculating the <span class="hlt">energy</span> diagram of asymmetric graded-<span class="hlt">band</span>-gap superlattices, linearized Poisson's equation has been solved for the two layers forming a period of the superlattice. The obtained coordinate dependences of edges of the conduction and valence <span class="hlt">bands</span> demonstrate substantial transformation of the shape of the <span class="hlt">energy</span> diagram at changing the period of the lattice and the ratio of width of the adjacent layers. The most marked changes in the <span class="hlt">energy</span> diagram take place when the period of lattice is comparable with the Debye screening length. In the case when the lattice period is much smaller that the Debye screening length, the <span class="hlt">energy</span> diagram has the shape of a sawtooth-like pattern.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NRL....12..203M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NRL....12..203M"><span>Calculation of <span class="hlt">Energy</span> Diagram of Asymmetric Graded-<span class="hlt">Band</span>-Gap Semiconductor Superlattices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Monastyrskii, Liubomyr S.; Sokolovskii, Bogdan S.; Alekseichyk, Mariya P.</p> <p>2017-03-01</p> <p>The paper theoretically investigates the peculiarities of <span class="hlt">energy</span> diagram of asymmetric graded-<span class="hlt">band</span>-gap superlattices with linear coordinate dependences of <span class="hlt">band</span> gap and electron affinity. For calculating the <span class="hlt">energy</span> diagram of asymmetric graded-<span class="hlt">band</span>-gap superlattices, linearized Poisson's equation has been solved for the two layers forming a period of the superlattice. The obtained coordinate dependences of edges of the conduction and valence <span class="hlt">bands</span> demonstrate substantial transformation of the shape of the <span class="hlt">energy</span> diagram at changing the period of the lattice and the ratio of width of the adjacent layers. The most marked changes in the <span class="hlt">energy</span> diagram take place when the period of lattice is comparable with the Debye screening length. In the case when the lattice period is much smaller that the Debye screening length, the <span class="hlt">energy</span> diagram has the shape of a sawtooth-like pattern.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20633853','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20633853"><span><span class="hlt">Energy</span> loss of ions at metal surfaces: <span class="hlt">Band</span>-structure effects</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Alducin, M.; Silkin, V.M.; Juaristi, J.I.; Chulkov, E.V.</p> <p>2003-03-01</p> <p>We study <span class="hlt">band</span>-structure effects on the <span class="hlt">energy</span> loss of protons scattered off the Cu (111) surface. The distance dependent stopping power for a projectile traveling parallel to the surface is calculated within the linear response theory. The self-consistent electronic response of the system is evaluated within the random-phase approximation. In order to characterize the surface <span class="hlt">band</span> structure, the electronic single-particle wave functions and <span class="hlt">energies</span> are obtained by solving the Schroedinger equation with a realistic one-dimensional model potential. This potential reproduces the main features of the Cu (111) surface: the <span class="hlt">energy</span> <span class="hlt">band</span> gap for electron motion along the surface normal, as well as the binding <span class="hlt">energy</span> of the occupied surface state and the first image state. Comparison of our results with those obtained within the jellium model allows us to characterize the <span class="hlt">band</span>-structure effects in the <span class="hlt">energy</span> loss of protons interacting with the Cu (111) surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvA..95c3605S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvA..95c3605S"><span>Signatures of the single-particle mobility edge in the <span class="hlt">ground-state</span> properties of Tonks-Girardeau and noninteracting Fermi gases in a bichromatic potential</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Settino, J.; Lo Gullo, N.; Sindona, A.; Goold, J.; Plastina, F.</p> <p>2017-03-01</p> <p>We explore the <span class="hlt">ground-state</span> properties of cold atomic gases focusing on the cases of noninteracting fermions and hard-core (Tonks-Girardeau) bosons, trapped by the combination of two potentials (bichromatic lattice) with incommensurate periods. For such systems, two limiting cases have been thoroughly established. In the tight-binding limit, the single-particle states in the lowest occupied <span class="hlt">band</span> show a localization transition, as the strength of the second potential is increased above a certain threshold. In the continuous limit, when the tight-binding approximation does not hold, a mobility edge is found, instead, whose position in <span class="hlt">energy</span> depends upon the strength of the second potential. Here, we study how the crossover from the discrete to the continuum behavior occurs, and prove that signatures of the localization transition and mobility edge clearly appear in the generic many-body properties of the systems. Specifically, we evaluate the momentum distribution, which is a routinely measured quantity in experiments with cold atoms, and demonstrate that, even in the presence of strong boson-boson interactions (infinite in the Tonks-Girardeau limit), the single-particle mobility edge can be observed in the <span class="hlt">ground-state</span> properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ChPhC..41a4102S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ChPhC..41a4102S"><span>Systematic study of α preformation probability of nuclear isomeric and <span class="hlt">ground</span> <span class="hlt">states</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Xiao-Dong; Wu, Xi-Jun; Zheng, Bo; Xiang, Dong; Guo, Ping; Li, Xiao-Hua</p> <p>2017-01-01</p> <p>In this paper, based on the two-potential approach combining with the isospin dependent nuclear potential, we systematically compare the α preformation probabilities of odd-A nuclei between nuclear isomeric states and <span class="hlt">ground</span> <span class="hlt">states</span>. The results indicate that during the process of α particle preforming, the low lying nuclear isomeric states are similar to <span class="hlt">ground</span> <span class="hlt">states</span>. Meanwhile, in the framework of single nucleon <span class="hlt">energy</span> level structure, we find that for nuclei with nucleon number below the magic numbers, the α preformation probabilities of high-spin states seem to be larger than low ones. For nuclei with nucleon number above the magic numbers, the α preformation probabilities of isomeric states are larger than those of <span class="hlt">ground</span> <span class="hlt">states</span>. Supported by National Natural Science Foundation of China (11205083), Construct Program of Key Discipline in Hunan Province, Research Foundation of Education Bureau of Hunan Province, China (15A159), Natural Science Foundation of Hunan Province, China (2015JJ3103, 2015JJ2123), Innovation Group of Nuclear and Particle Physics in USC, Hunan Provincial Innovation Foundation for Postgraduate (CX2015B398)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SuMi..104...93S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SuMi..104...93S"><span>The effects of polaronic mass and conduction <span class="hlt">band</span> non-parabolicity on a donor binding <span class="hlt">energy</span> under the simultaneous effect of pressure and temperature basing on the numerical FEM in a spherical quantum dot</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sali, A.; Kharbach, J.; Rezzouk, A.; Ouazzani Jamil, M.</p> <p>2017-04-01</p> <p>Basing on the numerical Finite Element Method (FEM), we have investigated the influences of polaronic mass and conduction <span class="hlt">band</span> non-parabolicity on the binding <span class="hlt">energy</span> of the <span class="hlt">ground</span> <span class="hlt">state</span> of an on-center hydrogenic donor impurity in a spherical GaAs / Ga1 - x AlxAs quantum dot structure. The calculations have been made with a realistic potential barrier height in the framework of the effective mass approximation including the combined effect of hydrostatic pressure and temperature. The donor binding <span class="hlt">energy</span> is computed as a function of dot size, Al concentration x , hydrostatic pressure and temperature both in the absence and presence of polaronic mass and conduction <span class="hlt">band</span> non-parabolicity effects. We have taken into account the electronic effective mass, dielectric constant, and conduction <span class="hlt">band</span> offset between the dot and barriers varying with pressure and temperature. It has been found that the binding <span class="hlt">energy</span> is strongly affected by the effect of polaronic mass and conduction <span class="hlt">band</span> non-parabolicity for narrow quantum dot and large Al concentration x. The results show again that the donor binding <span class="hlt">energy</span> increases linearly with the pressure in direct gap regime and its variation is larger for narrower dots only and drops slightly with the temperature. A good agreement is obtained with the existing literature values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21599379','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21599379"><span><span class="hlt">Ground-state</span> structures of atomic metallic hydrogen.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McMahon, Jeffrey M; Ceperley, David M</p> <p>2011-04-22</p> <p>Ab initio random structure searching using density functional theory is used to determine the <span class="hlt">ground-state</span> structures of atomic metallic hydrogen from 500 GPa to 5 TPa. Including proton zero-point motion within the harmonic approximation, we estimate that molecular hydrogen dissociates into a monatomic body-centered tetragonal structure near 500 GPa (r(s)=1.23) that remains stable to 1 TPa (r(s)=1.11). At higher pressures, hydrogen stabilizes in an …ABCABC… planar structure that is similar to the <span class="hlt">ground</span> <span class="hlt">state</span> of lithium, but with a different stacking sequence. With increasing pressure, this structure compresses to the face-centered cubic lattice near 3.5 TPa (r(s)=0.92).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26601219','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26601219"><span>The valence-fluctuating <span class="hlt">ground</span> <span class="hlt">state</span> of plutonium.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Janoschek, Marc; Das, Pinaki; Chakrabarti, Bismayan; Abernathy, Douglas L; Lumsden, Mark D; Lawrence, John M; Thompson, Joe D; Lander, Gerard H; Mitchell, Jeremy N; Richmond, Scott; Ramos, Mike; Trouw, Frans; Zhu, Jian-Xin; Haule, Kristjan; Kotliar, Gabriel; Bauer, Eric D</p> <p>2015-07-01</p> <p>A central issue in material science is to obtain understanding of the electronic correlations that control complex materials. Such electronic correlations frequently arise because of the competition of localized and itinerant electronic degrees of freedom. Although the respective limits of well-localized or entirely itinerant <span class="hlt">ground</span> <span class="hlt">states</span> are well understood, the intermediate regime that controls the functional properties of complex materials continues to challenge theoretical understanding. We have used neutron spectroscopy to investigate plutonium, which is a prototypical material at the brink between bonding and nonbonding configurations. Our study reveals that the <span class="hlt">ground</span> <span class="hlt">state</span> of plutonium is governed by valence fluctuations, that is, a quantum mechanical superposition of localized and itinerant electronic configurations as recently predicted by dynamical mean field theory. Our results not only resolve the long-standing controversy between experiment and theory on plutonium's magnetism but also suggest an improved understanding of the effects of such electronic dichotomy in complex materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DNP.DD002K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DNP.DD002K"><span><span class="hlt">Ground</span> <span class="hlt">state</span> occupation probabilities of neutrinoless double beta decay candidates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kotila, Jenni; Barea, Jose</p> <p>2015-10-01</p> <p>A better understanding of nuclear structure can offer important constraints on the calculation of 0 νββ nuclear matrix elements. A simple way to consider differences between initial and final states of neutrinoless double beta decay candidates is to look at the <span class="hlt">ground</span> <span class="hlt">state</span> occupation probabilities of initial and final nuclei. As is well known, microscopic interacting boson model (IBM-2) has found to be very useful in the description of detailed aspects of nuclear structure. In this talk I will present results for <span class="hlt">ground</span> <span class="hlt">state</span> occupation probabilities obtained using IBM-2 for several interesting candidates of 0 νββ -decay. Comparison with recent experimental results is also made. This work was supported Academy of Finland (Project 266437) and Chilean Ministry of Education (Fondecyt Grant No. 1150564),</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12431378','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12431378"><span>Eliminating zebrafish pbx proteins reveals a hindbrain <span class="hlt">ground</span> <span class="hlt">state</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Waskiewicz, Andrew Jan; Rikhof, Holly A; Moens, Cecilia B</p> <p>2002-11-01</p> <p>The vertebrate hindbrain is divided into serially homologous segments, the rhombomeres (r). Pbx and Hox proteins are hypothesized to form heterodimeric, DNA binding transcription complexes which specify rhombomere identities. Here, we show that eliminating zebrafish Lzr/Pbx4 and Pbx2 function prevents hindbrain segmentation and causes a wholesale anterior homeotic transformation of r2-r6, to r1 identity. We demonstrate that Pbx proteins interact with Hox paralog group 1 proteins to specify segment identities broadly within the hindbrain, and that this process involves the Pbx:Hox-1-dependent induction of Fgf signals in r4. We propose that in the absence of Pbx function, r2-r6 acquire a homogeneous <span class="hlt">ground</span> <span class="hlt">state</span> identity, that of r1, and that Pbx proteins, functioning primarily with their Hox partners, function to modify this <span class="hlt">ground</span> <span class="hlt">state</span> identity during normal hindbrain development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25314387','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25314387"><span>Quantum quenches in the thermodynamic limit. II. Initial <span class="hlt">ground</span> <span class="hlt">states</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rigol, Marcos</p> <p>2014-09-01</p> <p>A numerical linked-cluster algorithm was recently introduced to study quantum quenches in the thermodynamic limit starting from thermal initial states [M. Rigol, Phys. Rev. Lett. 112, 170601 (2014)]. Here, we tailor that algorithm to quenches starting from <span class="hlt">ground</span> <span class="hlt">states</span>. In particular, we study quenches from the <span class="hlt">ground</span> <span class="hlt">state</span> of the antiferromagnetic Ising model to the XXZ chain. Our results for spin correlations are shown to be in excellent agreement with recent analytical calculations based on the quench action method. We also show that they are different from the correlations in thermal equilibrium, which confirms the expectation that thermalization does not occur in general in integrable models even if they cannot be mapped to noninteracting ones.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1236683','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1236683"><span>The valence-fluctuating <span class="hlt">ground</span> <span class="hlt">state</span> of plutonium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Janoschek, Marc; Das, Pinaki; Chakrabarti, Bismayan; Abernathy, Douglas L.; Lumsden, Mark D.; Lawrence, John M.; Thompson, Joe D.; Lander, Gerard H.; Mitchell, Jeremy N.; Richmond, Scott; Ramos, Mike; Trouw, Frans; Zhu, Jian -Xin; Haule, Kristjan; Kotliar, Gabriel; Bauer, Eric D.</p> <p>2015-07-10</p> <p>A central issue in material science is to obtain understanding of the electronic correlations that control complex materials. Such electronic correlations frequently arise because of the competition of localized and itinerant electronic degrees of freedom. Although the respective limits of well-localized or entirely itinerant <span class="hlt">ground</span> <span class="hlt">states</span> are well understood, the intermediate regime that controls the functional properties of complex materials continues to challenge theoretical understanding. We have used neutron spectroscopy to investigate plutonium, which is a prototypical material at the brink between bonding and nonbonding configurations. In addition, our study reveals that the <span class="hlt">ground</span> <span class="hlt">state</span> of plutonium is governed by valence fluctuations, that is, a quantum mechanical superposition of localized and itinerant electronic configurations as recently predicted by dynamical mean field theory. Our results not only resolve the long-standing controversy between experiment and theory on plutonium’s magnetism but also suggest an improved understanding of the effects of such electronic dichotomy in complex materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DMP.D1140Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DMP.D1140Y"><span>Coherent Control of <span class="hlt">Ground</span> <span class="hlt">State</span> NaK Molecules</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yan, Zoe; Park, Jee Woo; Loh, Huanqian; Will, Sebastian; Zwierlein, Martin</p> <p>2016-05-01</p> <p>Ultracold dipolar molecules exhibit anisotropic, tunable, long-range interactions, making them attractive for the study of novel states of matter and quantum information processing. We demonstrate the creation and control of 23 Na40 K molecules in their rovibronic and hyperfine <span class="hlt">ground</span> <span class="hlt">state</span>. By applying microwaves, we drive coherent Rabi oscillations of spin-polarized molecules between the rotational <span class="hlt">ground</span> <span class="hlt">state</span> (J=0) and J=1. The control afforded by microwave manipulation allows us to pursue engineered dipolar interactions via microwave dressing. By driving a two-photon transition, we are also able to observe Ramsey fringes between different J=0 hyperfine states, with coherence times as long as 0.5s. The realization of long coherence times between different molecular states is crucial for applications in quantum information processing. NSF, AFOSR- MURI, Alfred P. Sloan Foundation, DARPA-OLE</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPSJ...86c3707H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPSJ...86c3707H"><span><span class="hlt">Ground-State</span> Phase Diagram of S = 1 Diamond Chains</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hida, Kazuo; Takano, Ken'ichi</p> <p>2017-03-01</p> <p>We investigate the <span class="hlt">ground-state</span> phase diagram of a spin-1 diamond chain. Owing to a series of conservation laws, any eigenstate of this system can be expressed using the eigenstates of finite odd-length chains or infinite chains with spins 1 and 2. The <span class="hlt">ground</span> <span class="hlt">state</span> undergoes quantum phase transitions with varying λ, a parameter that controls frustration. Exact upper and lower bounds for the phase boundaries between these phases are obtained. The phase boundaries are determined numerically in the region not explored in a previous work [Takano et al., <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1088/0953-8984/8/35/009" xlink:type="simple">J. Phys.: Condens. Matter 8, 6405 (1996)</ext-link>].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4646783','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4646783"><span>The valence-fluctuating <span class="hlt">ground</span> <span class="hlt">state</span> of plutonium</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Janoschek, Marc; Das, Pinaki; Chakrabarti, Bismayan; Abernathy, Douglas L.; Lumsden, Mark D.; Lawrence, John M.; Thompson, Joe D.; Lander, Gerard H.; Mitchell, Jeremy N.; Richmond, Scott; Ramos, Mike; Trouw, Frans; Zhu, Jian-Xin; Haule, Kristjan; Kotliar, Gabriel; Bauer, Eric D.</p> <p>2015-01-01</p> <p>A central issue in material science is to obtain understanding of the electronic correlations that control complex materials. Such electronic correlations frequently arise because of the competition of localized and itinerant electronic degrees of freedom. Although the respective limits of well-localized or entirely itinerant <span class="hlt">ground</span> <span class="hlt">states</span> are well understood, the intermediate regime that controls the functional properties of complex materials continues to challenge theoretical understanding. We have used neutron spectroscopy to investigate plutonium, which is a prototypical material at the brink between bonding and nonbonding configurations. Our study reveals that the <span class="hlt">ground</span> <span class="hlt">state</span> of plutonium is governed by valence fluctuations, that is, a quantum mechanical superposition of localized and itinerant electronic configurations as recently predicted by dynamical mean field theory. Our results not only resolve the long-standing controversy between experiment and theory on plutonium’s magnetism but also suggest an improved understanding of the effects of such electronic dichotomy in complex materials. PMID:26601219</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NJPh...17g5016P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NJPh...17g5016P"><span>Two-photon pathway to ultracold <span class="hlt">ground</span> <span class="hlt">state</span> molecules of 23Na40K</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Jee Woo; Will, Sebastian A.; Zwierlein, Martin W.</p> <p>2015-07-01</p> <p>We report on high-resolution spectroscopy of ultracold fermionic 23Na40K Feshbach molecules, and identify a two-photon pathway to the rovibrational singlet <span class="hlt">ground</span> <span class="hlt">state</span> via a resonantly mixed B1Π ˜ c3Σ+intermediate state. Photoassociation in a 23Na-40K atomic mixture and one-photon spectroscopy on 23Na40K Feshbach molecules reveal about 20 vibrational levels of the electronically excited c3Σ+state. Two of these levels are found to be strongly perturbed by nearby B1Π levels via spin-orbit coupling, resulting in additional lines of dominant singlet character in the perturbed complex {{{B}}}1\\Pi | v=4> ˜ {{{c}}}3{Σ }+| v=25> , or of resonantly mixed character in {{{B}}}1\\Pi | v=12> ˜ {{{c}}}3{Σ }+| v=35> . The dominantly singlet level is used to locate the absolute rovibrational singlet <span class="hlt">ground</span> <span class="hlt">state</span> {{{X}}}1{Σ }+| v=0,J=0> via Autler-Townes spectroscopy. We demonstrate coherent two-photon coupling via dark state spectroscopy between the predominantly triplet Feshbach molecular state and the singlet <span class="hlt">ground</span> <span class="hlt">state</span>. Its binding <span class="hlt">energy</span> is measured to be 5212.0447(1) cm-1, a thousand-fold improvement in accuracy compared to previous determinations. In their absolute singlet <span class="hlt">ground</span> <span class="hlt">state</span>, 23Na40K molecules are chemically stable under binary collisions and possess a large electric dipole moment of 2.72 Debye. Our work thus paves the way towards the creation of strongly dipolar Fermi gases of NaK molecules.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ApPhL..96e2103A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ApPhL..96e2103A"><span>Electron <span class="hlt">energy</span> <span class="hlt">band</span> alignment at the (100)Si/MgO interface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Afanas'ev, V. V.; Stesmans, A.; Cherkaoui, K.; Hurley, P. K.</p> <p>2010-02-01</p> <p>The electron <span class="hlt">energy</span> <span class="hlt">band</span> diagram at the (100)Si/MgO interface is characterized using internal photoemission of electrons and holes from Si into the oxide. For the as-deposited amorphous MgO the interface barriers correspond to a <span class="hlt">band</span> gap width of 6.1 eV, i.e., much lower than the conventionally assumed bulk crystal value (7.83 eV). The annealing-induced crystallization of MgO mostly affects the <span class="hlt">energy</span> of the valence <span class="hlt">band</span> while the conduction <span class="hlt">band</span> bottom retains its <span class="hlt">energy</span> position at 3.37±0.05 eV above the top of the silicon valence <span class="hlt">band</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7504E..0GG','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7504E..0GG"><span>Ultrafast laser-induced modifications of <span class="hlt">energy</span> <span class="hlt">bands</span> of non-metal crystals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gruzdev, Vitaly</p> <p>2009-10-01</p> <p>Ultrafast laser-induced variations of electron <span class="hlt">energy</span> <span class="hlt">bands</span> of transparent solids significantly influence ionization and conduction-<span class="hlt">band</span> electron absorption driving the initial stage of laser-induced damage (LID). The mechanisms of the variations are attributed to changing electron functions from bonding to anti-bonding configuration via laser-induced ionization; laser-driven electron oscillations in quasi-momentum space; and direct distortion of the inter-atomic potential by electric field of laser radiation. The ionization results in the <span class="hlt">band</span>-structure modification via accumulation of broken chemical bonds between atoms and provides significant contribution to the overall modification only when enough excited electrons are accumulated in the conduction <span class="hlt">band</span>. The oscillations are associated with modification of electron <span class="hlt">energy</span> by pondermotive potential of the oscillations. The direct action of radiation's electric field leads to specific high-frequency Franz-Keldysh effect (FKE) spreading the allowed electron states into the <span class="hlt">bands</span> of forbidden <span class="hlt">energy</span>. Those processes determine the effective <span class="hlt">band</span> gap that is a laser-driven <span class="hlt">energy</span> gap between the modified electron <span class="hlt">energy</span> <span class="hlt">bands</span>. Among those mechanisms, the latter two provide reversible <span class="hlt">band</span>-structure modification that takes place from the beginning of the ionization and are, therefore, of special interest due to their strong influence on the initial stage of the ionization. The pondermotive potential results either in monotonous increase or oscillatory variations of the effective <span class="hlt">band</span> gap that has been taken into account in some ionization models. The classical FKE provides decrease of the <span class="hlt">band</span> gap. We analyzing the competition between those two opposite trends of the effective-<span class="hlt">band</span>-gap variations and discuss applications of those effects for considerations of the laser-induced damage and its threshold in transparent solids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/40277119','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/40277119"><span><span class="hlt">Ground</span> <span class="hlt">state</span> nonuniversality in the random-field Ising model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Duxbury, P. M.; Meinke, J. H.</p> <p>2001-09-01</p> <p>Two attractive and often used ideas, namely, universality and the concept of a zero-temperature fixed point, are violated in the infinite-range random-field Ising model. In the <span class="hlt">ground</span> <span class="hlt">state</span> we show that the exponents can depend continuously on the disorder and so are nonuniversal. However, we also show that at finite temperature the thermal order-parameter exponent 1/2 is restored so that temperature is a relevant variable. Broader implications of these results are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22591311','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22591311"><span>Electronic and <span class="hlt">ground</span> <span class="hlt">state</span> properties of ThTe</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bhardwaj, Purvee Singh, Sadhna</p> <p>2016-05-06</p> <p>The electronic properties of ThTe in cesium chloride (CsCl, B2) structure are investigated in the present paper. To study the <span class="hlt">ground</span> <span class="hlt">state</span> properties of thorium chalcogenide, the first principle calculations have been calculated. The bulk properties, including lattice constant, bulk modulus and its pressure derivative are obtained. The calculated equilibrium structural parameters are in good agreement with the available experimental and theoretical results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPSJ...85g4707N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPSJ...85g4707N"><span>Multi-<span class="hlt">band</span> Eilenberger Theory of Superconductivity: Systematic Low-<span class="hlt">Energy</span> Projection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nagai, Yuki; Nakamura, Hiroki</p> <p>2016-07-01</p> <p>We propose the general multi-<span class="hlt">band</span> quasiclassical Eilenberger theory of superconductivity to describe quasiparticle excitations in inhomogeneous systems. With the use of low-<span class="hlt">energy</span> projection matrix, the M-<span class="hlt">band</span> quasiclassical Eilenberger equations are systematically obtained from N-<span class="hlt">band</span> Gor'kov equations. Here M is the internal degrees of freedom in the <span class="hlt">bands</span> crossing the Fermi <span class="hlt">energy</span> and N is the degree of freedom in a model. Our framework naturally includes inter-<span class="hlt">band</span> off-diagonal elements of Green's functions, which have usually been neglected in previous multi-<span class="hlt">band</span> quasiclassical frameworks. The resultant multi-<span class="hlt">band</span> Eilenberger and Andreev equations are similar to the single-<span class="hlt">band</span> ones, except for multi-<span class="hlt">band</span> effects. The multi-<span class="hlt">band</span> effects can exhibit the non-locality and the anisotropy in the mapped systems. Our framework can be applied to an arbitrary Hamiltonian (e.g., a tight-binding Hamiltonian derived by the first-principle calculation). As examples, we use our framework in various kinds of systems, such as noncentrosymmetric superconductor CePt3Si, three-orbital model for Sr2RuO4, heavy fermion CeCoIn5/YbCoIn5 superlattice, a topological superconductor with the strong spin-orbit coupling CuxBi2Se3, and a surface system on a topological insulator.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009NJPh...11g3032A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009NJPh...11g3032A"><span>Observation of a kilogram-scale oscillator near its quantum <span class="hlt">ground</span> <span class="hlt">state</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abbott, B.; Abbott, R.; Adhikari, R.; Ajith, P.; Allen, B.; Allen, G.; Amin, R.; Anderson, S. B.; Anderson, W. G.; Arain, M. A.; Araya, M.; Armandula, H.; Armor, P.; Aso, Y.; Aston, S.; Aufmuth, P.; Aulbert, C.; Babak, S.; Ballmer, S.; Bantilan, H.; Barish, B. C.; Barker, C.; Barker, D.; Barr, B.; Barriga, P.; Barton, M. A.; Bastarrika, M.; Bayer, K.; Betzwieser, J.; Beyersdorf, P. T.; Bilenko, I. A.; Billingsley, G.; Biswas, R.; Black, E.; Blackburn, K.; Blackburn, L.; Blair, D.; Bland, B.; Bodiya, T. P.; Bogue, L.; Bork, R.; Boschi, V.; Bose, S.; Brady, P. R.; Braginsky, V. B.; Brau, J. E.; Brinkmann, M.; Brooks, A.; Brown, D. A.; Brunet, G.; Bullington, A.; Buonanno, A.; Burmeister, O.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Camp, J. B.; Cannizzo, J.; Cannon, K.; Cao, J.; Cardenas, L.; Casebolt, T.; Castaldi, G.; Cepeda, C.; Chalkley, E.; Charlton, P.; Chatterji, S.; Chelkowski, S.; Chen, Y.; Christensen, N.; Clark, D.; Clark, J.; Cokelaer, T.; Conte, R.; Cook, D.; Corbitt, T.; Coyne, D.; Creighton, J. D. E.; Cumming, A.; Cunningham, L.; Cutler, R. M.; Dalrymple, J.; Danilishin, S.; Danzmann, K.; Davies, G.; DeBra, D.; Degallaix, J.; Degree, M.; Dergachev, V.; Desai, S.; DeSalvo, R.; Dhurandhar, S.; Díaz, M.; Dickson, J.; Dietz, A.; Donovan, F.; Dooley, K. L.; Doomes, E. E.; Drever, R. W. P.; Duke, I.; Dumas, J.-C.; Dupuis, R. J.; Dwyer, J. G.; Echols, C.; Effler, A.; Ehrens, P.; Espinoza, E.; Etzel, T.; Evans, T.; Fairhurst, S.; Fan, Y.; Fazi, D.; Fehrmann, H.; Fejer, M. M.; Finn, L. S.; Flasch, K.; Fotopoulos, N.; Freise, A.; Frey, R.; Fricke, T.; Fritschel, P.; Frolov, V. V.; Fyffe, M.; Garofoli, J.; Gholami, I.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Goda, K.; Goetz, E.; Goggin, L.; González, G.; Gossler, S.; Gouaty, R.; Grant, A.; Gras, S.; Gray, C.; Gray, M.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Grimaldi, F.; Grosso, R.; Grote, H.; Grunewald, S.; Guenther, M.; Gustafson, E. K.; Gustafson, R.; Hage, B.; Hallam, J. M.; Hammer, D.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G.; Harstad, E.; Hayama, K.; Hayler, T.; Heefner, J.; Heng, I. S.; Hennessy, M.; Heptonstall, A.; Hewitson, M.; Hild, S.; Hirose, E.; Hoak, D.; Hosken, D.; Hough, J.; Huttner, S. H.; Ingram, D.; Ito, M.; Ivanov, A.; Johnson, B.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kamat, S.; Kanner, J.; Kasprzyk, D.; Katsavounidis, E.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Kells, W.; Keppel, D. G.; Khalili, F. Ya; Khan, R.; Khazanov, E.; Kim, C.; King, P.; Kissel, J. S.; Klimenko, S.; Kokeyama, K.; Kondrashov, V.; Kopparapu, R. K.; Kozak, D.; Kozhevatov, I.; Krishnan, B.; Kwee, P.; Lam, P. K.; Landry, M.; Lang, M. M.; Lantz, B.; Lazzarini, A.; Lei, M.; Leindecker, N.; Leonhardt, V.; Leonor, I.; Libbrecht, K.; Lin, H.; Lindquist, P.; Lockerbie, N. A.; Lodhia, D.; Lormand, M.; Lu, P.; Lubinski, M.; Lucianetti, A.; Lück, H.; Machenschalk, B.; MacInnis, M.; Mageswaran, M.; Mailand, K.; Mandic, V.; Márka, S.; Márka, Z.; Markosyan, A.; Markowitz, J.; Maros, E.; Martin, I.; Martin, R. M.; Marx, J. N.; Mason, K.; Matichard, F.; Matone, L.; Matzner, R.; Mavalvala, N.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McHugh, M.; McIntyre, G.; McIvor, G.; McKechan, D.; McKenzie, K.; Meier, T.; Melissinos, A.; Mendell, G.; Mercer, R. A.; Meshkov, S.; Messenger, C. J.; Meyers, D.; Miao, H.; Miller, J.; Minelli, J.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Miyakawa, O.; Moe, B.; Mohanty, S.; Moreno, G.; Mossavi, K.; Mow-Lowry, C.; Mueller, G.; Mukherjee, S.; Mukhopadhyay, H.; Müller-Ebhardt, H.; Munch, J.; Murray, P.; Myers, E.; Myers, J.; Nash, T.; Nelson, J.; Newton, G.; Nishizawa, A.; Numata, K.; O'Dell, J.; Ogin, G.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Pan, Y.; Pankow, C.; Papa, M. A.; Parameshwaraiah, V.; Patel, P.; Pedraza, M.; Penn, S.; Perreca, A.; Petrie, T.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Plissi, M. V.; Postiglione, F.; Principe, M.; Prix, R.; Quetschke, V.; Raab, F.; Rabeling, D. S.; Radkins, H.; Rainer, N.; Rakhmanov, M.; Ramsunder, M.; Rehbein, H.; Reid, S.; Reitze, D. H.; Riesen, R.; Riles, K.; Rivera, B.; Robertson, N. A.; Robinson, C.; Robinson, E. L.; Roddy, S.; Rodriguez, A.; Rogan, A. M.; Rollins, J.; Romano, J. D.; Romie, J.; Route, R.; Rowan, S.; Rüdiger, A.; Ruet, L.; Russell, P.; Ryan, K.; Sakata, S.; Samidi, M.; Sancho de la Jordana, L.; Sandberg, V.; Sannibale, V.; Saraf, S.; Sarin, P.; Sathyaprakash, B. S.; Sato, S.; Saulson, P. R.; Savage, R.; Savov, P.; Schediwy, S. W.; Schilling, R.; Schnabel, R.; Schofield, R.; Schutz, B. F.; Schwinberg, P.; Scott, S. M.; Searle, A. C.; Sears, B.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Shawhan, P.; Shoemaker, D. H.; Sibley, A.; Siemens, X.; Sigg, D.; Sinha, S.; Sintes, A. M.; Slagmolen, B. J. J.; Slutsky, J.; Smith, J. R.; Smith, M. R.; Smith, N. D.; Somiya, K.; Sorazu, B.; Stein, L. C.; Stochino, A.; Stone, R.; Strain, K. A.; Strom, D. M.; Stuver, A.; Summerscales, T. Z.; Sun, K.-X.; Sung, M.; Sutton, P. J.; Takahashi, H.; Tanner, D. B.; Taylor, R.; Taylor, R.; Thacker, J.; Thorne, K. A.; Thorne, K. S.; Thüring, A.; Tokmakov, K. V.; Torres, C.; Torrie, C.; Traylor, G.; Trias, M.; Tyler, W.; Ugolini, D.; Ulmen, J.; Urbanek, K.; Vahlbruch, H.; Van Den Broeck, C.; van der Sluys, M.; Vass, S.; Vaulin, R.; Vecchio, A.; Veitch, J.; Veitch, P.; Villar, A.; Vorvick, C.; Vyatchanin, S. P.; Waldman, S. J.; Wallace, L.; Ward, H.; Ward, R.; Weinert, M.; Weinstein, A.; Weiss, R.; Wen, S.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; Whiting, B. F.; Wilkinson, C.; Willems, P. A.; Williams, H. R.; Williams, L.; Willke, B.; Wilmut, I.; Winkler, W.; Wipf, C. C.; Wiseman, A. G.; Woan, G.; Wooley, R.; Worden, J.; Wu, W.; Yakushin, I.; Yamamoto, H.; Yan, Z.; Yoshida, S.; Zanolin, M.; Zhang, J.; Zhang, L.; Zhao, C.; Zotov, N.; Zucker, M.; Zweizig, J.; LIGO Scientific Collaboration</p> <p>2009-07-01</p> <p>We introduce a novel cooling technique capable of approaching the quantum <span class="hlt">ground</span> <span class="hlt">state</span> of a kilogram-scale system—an interferometric gravitational wave detector. The detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) operate within a factor of 10 of the standard quantum limit (SQL), providing a displacement sensitivity of 10-18 m in a 100 Hz <span class="hlt">band</span> centered on 150 Hz. With a new feedback strategy, we dynamically shift the resonant frequency of a 2.7 kg pendulum mode to lie within this optimal <span class="hlt">band</span>, where its effective temperature falls as low as 1.4 μK, and its occupation number reaches about 200 quanta. This work shows how the exquisite sensitivity necessary to detect gravitational waves can be made available to probe the validity of quantum mechanics on an enormous mass scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMIN11D1639H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMIN11D1639H"><span>The Fair in Unfair Quantum <span class="hlt">Ground-state</span> Sampling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hen, I.; Martin-Mayor, V.; Zhang, B.</p> <p>2016-12-01</p> <p>The debate around the potential superiority of quantum annealers over their classical counterparts has been ongoing since the inception of the field by Kadowaki and Nishimori close to two decades ago. Recent technological advancements in the field, which have led to the manufacture of experimental prototypes of quantum annealing optimizers with sizes approaching the practical regime have reignited this discussion. However, the demonstration of quantum annealing speedups remains to this day an elusive albeit coveted goal. Here, we examine the power of quantum annealers to provide quantum enhancements when used as samplers from distributions of bit configurations rather than as <span class="hlt">ground</span> <span class="hlt">state</span> optimizers. We study, both numerically by simulating stoquastic and as non-stoquastic quantum annealing processes, and experimentally using the D-Wave Two putative quantum annealing optimizer, the ability of quantum annealers to sample the <span class="hlt">ground</span> <span class="hlt">state</span> manifolds of spin glasses -- a type of problems that appears in diverse areas of science and technology such has circuit fault detection, verification & validation, graph isomorphism and more. We show that quantum annealers sample the <span class="hlt">ground</span> <span class="hlt">state</span> manifolds of spin glasses potentially very differently than classical algorithms, and may potentially serve as a powerful tool in complementing traditional approaches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CMaPh.347..983G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CMaPh.347..983G"><span>Periodic Striped <span class="hlt">Ground</span> <span class="hlt">States</span> in Ising Models with Competing Interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Giuliani, Alessandro; Seiringer, Robert</p> <p>2016-11-01</p> <p>We consider Ising models in two and three dimensions, with short range ferromagnetic and long range, power-law decaying, antiferromagnetic interactions. We let J be the ratio between the strength of the ferromagnetic to antiferromagnetic interactions. The competition between these two kinds of interactions induces the system to form domains of minus spins in a background of plus spins, or vice versa. If the decay exponent p of the long range interaction is larger than d + 1, with d the space dimension, this happens for all values of J smaller than a critical value J c ( p), beyond which the <span class="hlt">ground</span> <span class="hlt">state</span> is homogeneous. In this paper, we give a characterization of the infinite volume <span class="hlt">ground</span> <span class="hlt">states</span> of the system, for p > 2 d and J in a left neighborhood of J c ( p). In particular, we prove that the quasi-one-dimensional states consisting of infinite stripes ( d = 2) or slabs ( d = 3), all of the same optimal width and orientation, and alternating magnetization, are infinite volume <span class="hlt">ground</span> <span class="hlt">states</span>. Our proof is based on localization bounds combined with reflection positivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21528948','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21528948"><span>Condensed <span class="hlt">ground</span> <span class="hlt">states</span> of frustrated Bose-Hubbard models</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moeller, G.; Cooper, N. R.</p> <p>2010-12-15</p> <p>We study theoretically the <span class="hlt">ground</span> <span class="hlt">states</span> of two-dimensional Bose-Hubbard models which are frustrated by gauge fields. Motivated by recent proposals for the implementation of optically induced gauge potentials, we focus on the situation in which the imposed gauge fields give rise to a pattern of staggered fluxes of magnitude {alpha} and alternating in sign along one of the principal axes. For {alpha}=1/2 this model is equivalent to the case of uniform flux per plaquette n{sub {phi}=}1/2, which, in the hard-core limit, realizes the 'fully frustrated' spin-1/2 XY model. We show that the mean-field <span class="hlt">ground</span> <span class="hlt">states</span> of this frustrated Bose-Hubbard model typically break translational symmetry. Given the presence of both a non-zero superfluid fraction and translational symmetry breaking, these phases are supersolid. We introduce a general numerical technique to detect broken symmetry condensates in exact diagonalization studies. Using this technique we show that, for all cases studied, the <span class="hlt">ground</span> <span class="hlt">state</span> of the Bose-Hubbard model with staggered flux {alpha} is condensed, and we obtain quantitative determinations of the condensate fraction. We discuss the experimental consequences of our results. In particular, we explain the meaning of gauge invariance in ultracold-atom systems subject to optically induced gauge potentials and show how the ability to imprint phase patterns prior to expansion can allow very useful additional information to be extracted from expansion images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19256978','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19256978"><span>Numerical methods for computing the <span class="hlt">ground</span> <span class="hlt">state</span> of spin-1 Bose-Einstein condensates in a uniform magnetic field.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lim, Fong Yin; Bao, Weizhu</p> <p>2008-12-01</p> <p>We propose efficient and accurate numerical methods for computing the <span class="hlt">ground-state</span> solution of spin-1 Bose-Einstein condensates subjected to a uniform magnetic field. The key idea in designing the numerical method is based on the normalized gradient flow with the introduction of a third normalization condition, together with two physical constraints on the conservation of total mass and conservation of total magnetization. Different treatments of the Zeeman <span class="hlt">energy</span> terms are found to yield different numerical accuracies and stabilities. Numerical comparison between different numerical schemes is made, and the best scheme is identified. The numerical scheme is then applied to compute the condensate <span class="hlt">ground</span> <span class="hlt">state</span> in a harmonic plus optical lattice potential, and the effect of the periodic potential, in particular to the relative population of each hyperfine component, is investigated through comparison to the condensate <span class="hlt">ground</span> <span class="hlt">state</span> in a pure harmonic trap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25247447','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25247447"><span><span class="hlt">Energy</span> <span class="hlt">band</span> gap and optical transition of metal ion modified double crossover DNA lattices.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dugasani, Sreekantha Reddy; Ha, Taewoo; Gnapareddy, Bramaramba; Choi, Kyujin; Lee, Junwye; Kim, Byeonghoon; Kim, Jae Hoon; Park, Sung Ha</p> <p>2014-10-22</p> <p>We report on the <span class="hlt">energy</span> <span class="hlt">band</span> gap and optical transition of a series of divalent metal ion (Cu(2+), Ni(2+), Zn(2+), and Co(2+)) modified DNA (M-DNA) double crossover (DX) lattices fabricated on fused silica by the substrate-assisted growth (SAG) method. We demonstrate how the degree of coverage of the DX lattices is influenced by the DX monomer concentration and also analyze the <span class="hlt">band</span> gaps of the M-DNA lattices. The <span class="hlt">energy</span> <span class="hlt">band</span> gap of the M-DNA, between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO), ranges from 4.67 to 4.98 eV as judged by optical transitions. Relative to the <span class="hlt">band</span> gap of a pristine DNA molecule (4.69 eV), the <span class="hlt">band</span> gap of the M-DNA lattices increases with metal ion doping up to a critical concentration and then decreases with further doping. Interestingly, except for the case of Ni(2+), the onset of the second absorption <span class="hlt">band</span> shifts to a lower <span class="hlt">energy</span> until a critical concentration and then shifts to a higher <span class="hlt">energy</span> with further increasing the metal ion concentration, which is consistent with the evolution of electrical transport characteristics. Our results show that controllable metal ion doping is an effective method to tune the <span class="hlt">band</span> gap <span class="hlt">energy</span> of DNA-based nanostructures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARC50011G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARC50011G"><span><span class="hlt">Energy</span> Dependence and Scaling Property of Localization Length near a Gapped Flat <span class="hlt">Band</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ge, Li; Tureci, Hakan</p> <p></p> <p>Using a tight-binding model for a one-dimensional Lieb lattice, we show that the localization length near a gapped flat <span class="hlt">band</span> behaves differently from the typical Urbach tail in a <span class="hlt">band</span> gap: instead of reducing monotonically as the <span class="hlt">energy</span> E moves away from the flat <span class="hlt">band</span> <span class="hlt">energy</span> Ef, the presence of the flat <span class="hlt">band</span> causes a nonmonotonic <span class="hlt">energy</span> dependence of the localization length. This <span class="hlt">energy</span> dependence follows a scaling property when the <span class="hlt">energy</span> is within the spread (W) of uniformly distributed diagonal disorder, i.e. the localization length is only a function of (E-Ef)/W. Several other lattices are compared to distinguish the effect of the flat <span class="hlt">band</span> on the localization length, where we eliminate, shift, or duplicate the flat <span class="hlt">band</span>, without changing the dispersion relations of other <span class="hlt">bands</span>. Using the top right element of the Green's matrix, we derive an analytical relation between the density of states and the localization length, which shines light on these properties of the latter, including a summation rule for its inverse. This work is partially supported by NSF under Grant No. DMR-1506987.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22483186','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22483186"><span><span class="hlt">Energy</span> <span class="hlt">band</span> bowing parameter in MgZnO alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, Xu; Saito, Katsuhiko; Tanaka, Tooru; Nishio, Mitsuhiro; Guo, Qixin; Nagaoka, Takashi; Arita, Makoto</p> <p>2015-07-13</p> <p>We report on bandgap bowing parameters for wurtzite and cubic MgZnO alloys from a study of high quality and single phase films in all Mg content range. The Mg contents in the MgZnO films were accurately determined using the <span class="hlt">energy</span> dispersive spectrometer and X-ray photoelectron spectroscopy (XPS). The measurement of bandgap <span class="hlt">energies</span> by examining the onset of inelastic <span class="hlt">energy</span> loss in core-level atomic spectra from XPS is proved to be valid for determining the bandgap of MgZnO films. The dependence of the <span class="hlt">energy</span> bandgap on Mg content is found to deviate downwards from linearity. Fitting of the bandgap data resulted in two bowing parameters of 2.01 ± 0.04 eV and 1.48 ± 0.11 eV corresponding to wurtzite and cubic MgZnO films, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JAP...113u3509C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JAP...113u3509C"><span>Fe-substituted indium thiospinels: New intermediate <span class="hlt">band</span> semiconductors with better absorption of solar <span class="hlt">energy</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Ping; Chen, Haijie; Qin, Mingsheng; Yang, Chongyin; Zhao, Wei; Liu, Yufeng; Zhang, Wenqing; Huang, Fuqiang</p> <p>2013-06-01</p> <p>The indium thiospinels In2S3 and MgIn2S4 are promising host for the intermediated <span class="hlt">band</span> (IB) photovoltaic materials due to their ideal <span class="hlt">band</span> gap value. Here, the optical properties and electronic structure of Fe-doped In2S3 and MgIn2S4 have been investigated. All the Fe-substituted semiconductors exhibit two additional absorption <span class="hlt">bands</span> at about 0.7 and 1.25 eV, respectively. The results of first-principles calculations revealed that the Fe substituted at the octahedral In site would introduce a partially filled IB into the <span class="hlt">band</span> gap. Thanks to the formation of IB, the Fe-substituted semiconductors have the ability to absorb the photons with <span class="hlt">energies</span> below the <span class="hlt">band</span> gap. With the wide-spectrum absorption of solar <span class="hlt">energy</span>, these materials possess potential applications in photovoltaic domain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SSCom.152.1089M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SSCom.152.1089M"><span>First-principle study of <span class="hlt">energy</span> <span class="hlt">band</span> structure of armchair graphene nanoribbons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Fei; Guo, Zhankui; Xu, Kewei; Chu, Paul K.</p> <p>2012-07-01</p> <p>First-principle calculation is carried out to study the <span class="hlt">energy</span> <span class="hlt">band</span> structure of armchair graphene nanoribbons (AGNRs). Hydrogen passivation is found to be crucial to convert the indirect <span class="hlt">band</span> gaps into direct ones as a result of enhanced interactions between electrons and nuclei at the edge boundaries, as evidenced from the shortened bond length as well as the increased differential charge density. Ribbon width usually leads to the oscillatory variation of <span class="hlt">band</span> gaps due to quantum confinement no matter hydrogen passivated or not. Mechanical strain may change the crystal symmetry, reduce the overlapping integral of C-C atoms, and hence modify the <span class="hlt">band</span> gap further, which depends on the specific ribbon width sensitively. In practical applications, those effects will be hybridized to determine the <span class="hlt">energy</span> <span class="hlt">band</span> structure and subsequently the electronic properties of graphene. The results can provide insights into the design of carbon-based devices.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20085246','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20085246"><span>Scaling behavior of electronic excitations in assemblies of molecules with degenerate <span class="hlt">ground</span> <span class="hlt">states</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fan, H-J; Perkins, C; Ortoleva, P J</p> <p>2010-02-11</p> <p>The behavior of long space-time excitations in many-electron systems with <span class="hlt">ground</span> <span class="hlt">state</span> degeneracy is explored via multiscale analysis. The analysis starts with an ansatz for the wave function's dual dependence on the N-electron configuration (i.e., both by direct means and by indirect means via a set of order parameters). It is shown that a Dirac-like equation form of the wave equation emerges in the limit where the ratio epsilon (of the average nearest-neighbor distance to the characteristic length of the long-scale phenomenon of interest) is small. Examples of the long scale are the size of a quantum dot, nanotube, or wavelength of a density disturbance. The velocities in the Dirac-like equation are the transition moments of the single-particle momentum operator connecting degenerate <span class="hlt">ground</span> <span class="hlt">states</span>. While detailed <span class="hlt">band</span> structure and the independent quasi-particle picture could underlie the behavior of some systems (as commonly suggested for graphene), the present scaling law results show it is not necessarily the only explanation. Rather, it can follow from the scaling properties of low-lying, long spatial scale excitations and <span class="hlt">ground</span> <span class="hlt">state</span> degeneracy, even in strongly interacting systems. The generality of our findings suggests graphene may be just one of many examples of Dirac-like equation behavior. A preliminary validation of our quantum scaling law for molecular arrays is presented. As our scaling law constitutes a coarse-grained wave equation, path integral or other methods derived from it hold great promise for calibration-free, long-time simulation of many-particle quantum systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.H23I..04H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.H23I..04H"><span>Analytical solutions for bacterial <span class="hlt">energy</span> taxis (chemotaxis): traveling bacterial <span class="hlt">bands</span> and their role in groundwater remediation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hilpert, M.; Long, W.</p> <p>2007-12-01</p> <p>Motile bacteria may form <span class="hlt">bands</span> that travel with a constant speed of propagation through a medium containing a dissolved substrate, to which they respond <span class="hlt">energy</span> tactically. We generalize the analytical solution by Keller and Segel for such <span class="hlt">bands</span> by accounting for (1) the presence of a porous medium, (2) substrate consumption described by a Monod kinetics model, and (3) an <span class="hlt">energy</span> tactic response model derived by Rivero et al. We also comment on the potential role of traveling bacterial <span class="hlt">bands</span> in the remediation of groundwater contamination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhRvC..88c4306J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhRvC..88c4306J"><span>Anharmonicity of the excited octupole <span class="hlt">band</span> in actinides using supersymmetric quantum mechanics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jolos, R. V.; von Brentano, P.; Casten, R. F.</p> <p>2013-09-01</p> <p>Background: Low-lying octupole collective excitations play an important role in the description of the structure of nuclei in the actinide region. <span class="hlt">Ground</span> <span class="hlt">state</span> alternating parity rotational <span class="hlt">bands</span> combining both positive and negative parity states are known in several nuclei. However, only recently it has been discovered in 240Pu an excited positive parity rotational <span class="hlt">band</span> having an octupole nature and demonstrating strong anharmonicity of the octupole motion in the <span class="hlt">band</span> head <span class="hlt">energies</span>.Purpose: To suggest a model describing both <span class="hlt">ground</span> <span class="hlt">state</span> and excited alternating parity <span class="hlt">bands</span>, which includes a description of the anharmonic effects in the bandhead excitation <span class="hlt">energies</span> and can be used to predict the <span class="hlt">energies</span> of the excited rotational <span class="hlt">bands</span> of octupole nature and the E1 transition probabilities.Methods: The mathematical technique of the supersymmetric quantum mechanics with a collective Hamiltonian depending only on the octupole collective variable which keeps axial symmetry is used to describe the <span class="hlt">ground</span> <span class="hlt">state</span> and excited alternating parity rotational <span class="hlt">bands</span>.Results: The excitation <span class="hlt">energies</span> of the states belonging to the lowest negative parity and the excited positive parity <span class="hlt">bands</span> are calculated for 232Th, 238U, and 240Pu. The E1 transition matrix elements are also calculated for 240Pu.Conclusions: It is shown that the suggested model describes the excitation <span class="hlt">energies</span> of the states of the lowest negative parity <span class="hlt">band</span> with the accuracy around 10 keV. The anharmonicity in the bandhead <span class="hlt">energy</span> of the excited positive parity <span class="hlt">band</span> is described also. The bandhead <span class="hlt">energy</span> of the excited positive parity <span class="hlt">band</span> is described with the accuracy around 100 keV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvA..93f3610N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvA..93f3610N"><span>Competing <span class="hlt">ground</span> <span class="hlt">states</span> of strongly correlated bosons in the Harper-Hofstadter-Mott model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Natu, Stefan S.; Mueller, Erich J.; Das Sarma, S.</p> <p>2016-06-01</p> <p>Using an efficient cluster approach, we study the physics of two-dimensional lattice bosons in a strong magnetic field in the regime where the tunneling is much weaker than the on-site interaction strength. We study both the dilute, hard-core bosons at filling factors much smaller than unity occupation per site and the physics in the vicinity of the superfluid-Mott lobes as the density is tuned away from unity. For hard-core bosons, we carry out extensive numerics for a fixed flux per plaquette ϕ =1 /5 and ϕ =1 /3 . At large flux, the lowest-<span class="hlt">energy</span> state is a strongly correlated superfluid, analogous to He-4, in which the order parameter is dramatically suppressed, but nonzero. At filling factors ν =1 /2 ,1 , we find competing incompressible states which are metastable. These appear to be commensurate density wave states. For small flux, the situation is reversed and the <span class="hlt">ground</span> <span class="hlt">state</span> at ν =1 /2 is an incompressible density wave solid. Here, we find a metastable lattice supersolid phase, where superfluidity and density wave order coexist. We then perform careful numerical studies of the physics near the vicinity of the Mott lobes for ϕ =1 /2 and ϕ =1 /4 . At ϕ =1 /2 , the superfluid <span class="hlt">ground</span> <span class="hlt">state</span> has commensurate density wave order. At ϕ =1 /4 , incompressible phases appear outside the Mott lobes at densities n =1.125 and n =1.25 , corresponding to filling fractions ν =1 /2 and 1, respectively. These phases, which are absent in single-site mean-field theory, are metastable and have slightly higher <span class="hlt">energy</span> than the superfluid, but the <span class="hlt">energy</span> difference between them shrinks rapidly with increasing cluster size, suggestive of an incompressible <span class="hlt">ground</span> <span class="hlt">state</span>. We thus explore the interplay between Mott physics, magnetic Landau levels, and superfluidity, finding a rich phase diagram of competing compressible and incompressible states.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvL.117x3401M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvL.117x3401M"><span>Dynamics of a <span class="hlt">Ground-State</span> Cooled Ion Colliding with Ultracold Atoms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meir, Ziv; Sikorsky, Tomas; Ben-shlomi, Ruti; Akerman, Nitzan; Dallal, Yehonatan; Ozeri, Roee</p> <p>2016-12-01</p> <p>Ultracold atom-ion mixtures are gaining increasing interest due to their potential applications in ultracold and state-controlled chemistry, quantum computing, and many-body physics. Here, we studied the dynamics of a single <span class="hlt">ground-state</span> cooled ion during few, to many, Langevin (spiraling) collisions with ultracold atoms. We measured the ion's <span class="hlt">energy</span> distribution and observed a clear deviation from the Maxwell-Boltzmann distribution, characterized by an exponential tail, to a power-law distribution best described by a Tsallis function. Unlike previous experiments, the <span class="hlt">energy</span> scale of atom-ion interactions is not determined by either the atomic cloud temperature or the ion's trap residual excess-micromotion <span class="hlt">energy</span>. Instead, it is determined by the force the atom exerts on the ion during a collision which is then amplified by the trap dynamics. This effect is intrinsic to ion Paul traps and sets the lower bound of atom-ion steady-state interaction <span class="hlt">energy</span> in these systems. Despite the fact that our system is eventually driven out of the ultracold regime, we are capable of studying quantum effects by limiting the interaction to the first collision when the ion is initialized in the <span class="hlt">ground</span> <span class="hlt">state</span> of the trap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28009205','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28009205"><span>Dynamics of a <span class="hlt">Ground-State</span> Cooled Ion Colliding with Ultracold Atoms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meir, Ziv; Sikorsky, Tomas; Ben-Shlomi, Ruti; Akerman, Nitzan; Dallal, Yehonatan; Ozeri, Roee</p> <p>2016-12-09</p> <p>Ultracold atom-ion mixtures are gaining increasing interest due to their potential applications in ultracold and state-controlled chemistry, quantum computing, and many-body physics. Here, we studied the dynamics of a single <span class="hlt">ground-state</span> cooled ion during few, to many, Langevin (spiraling) collisions with ultracold atoms. We measured the ion's <span class="hlt">energy</span> distribution and observed a clear deviation from the Maxwell-Boltzmann distribution, characterized by an exponential tail, to a power-law distribution best described by a Tsallis function. Unlike previous experiments, the <span class="hlt">energy</span> scale of atom-ion interactions is not determined by either the atomic cloud temperature or the ion's trap residual excess-micromotion <span class="hlt">energy</span>. Instead, it is determined by the force the atom exerts on the ion during a collision which is then amplified by the trap dynamics. This effect is intrinsic to ion Paul traps and sets the lower bound of atom-ion steady-state interaction <span class="hlt">energy</span> in these systems. Despite the fact that our system is eventually driven out of the ultracold regime, we are capable of studying quantum effects by limiting the interaction to the first collision when the ion is initialized in the <span class="hlt">ground</span> <span class="hlt">state</span> of the trap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..MARF29007B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..MARF29007B"><span>Extremal Optimization for <span class="hlt">Ground</span> <span class="hlt">States</span> of the Sherrington-Kirkpatrick Spin Glass with Levy Bonds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boettcher, Stefan</p> <p>2013-03-01</p> <p>Using the Extremal Optimization heuristic (EO),[3] <span class="hlt">ground</span> <span class="hlt">states</span> of the SK-spin glass are studied with bonds J distributed according to a Levy distribution P (J) ~ 1 /| J | 1 + α with | J | > 1 and 1 < α < 4 . The variation of the <span class="hlt">energy</span> densities with α, their finite-size corrections, their fluctuations, and their local field distribution are analyzed and compared with those for the SK model with Gaussian bonds.[4] We find that the <span class="hlt">energies</span> attain universally the Parisi-<span class="hlt">energy</span> of the SK when the second moment of P(J) exists (α > 2). They compare favorably with recent one-step replica symmetry breaking predictions well below α = 2 . Near α = 2 , the simulations deviate significantly from theoretical expectations. The finite-size corrections exponent ω decays from the putative SK value ωSK =2/3 already well above α = 2 . The exponent ρ for the scaling of <span class="hlt">ground</span> <span class="hlt">state</span> <span class="hlt">energy</span> fluctuations with system size decays linearly from its SK value for decreasing α and vanishes at α = 1 . Supported through NSF grant DMR-#1207431</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2685927','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2685927"><span>Klf4 reverts developmentally programmed restriction of <span class="hlt">ground</span> <span class="hlt">state</span> pluripotency</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Guo, Ge; Yang, Jian; Nichols, Jennifer; Hall, John Simon; Eyres, Isobel; Mansfield, William; Smith, Austin</p> <p>2009-01-01</p> <p>Summary Mouse embryonic stem (ES) cells derived from pluripotent early epiblast contribute functionally differentiated progeny to all foetal lineages of chimaeras. By contrast, epistem cell (EpiSC) lines from post-implantation epithelialised epiblast are unable to colonise the embryo even though they express the core pluripotency genes Oct4, Sox2 and Nanog. We examined interconversion between these two cell types. ES cells can readily become EpiSCs in response to growth factor cues. By contrast, EpiSCs do not change into ES cells. We exploited PiggyBac transposition to introduce a single reprogramming factor, Klf4, into EpiSCs. No effect was apparent in EpiSC culture conditions, but in <span class="hlt">ground</span> <span class="hlt">state</span> ES cell conditions a fraction of cells formed undifferentiated colonies. These EpiSC-derived induced pluripotent stem (Epi-iPS) cells activated expression of ES cell-specific transcripts including endogenous Klf4, and downregulated markers of lineage specification. X chromosome silencing in female cells, a feature of the EpiSC state, was erased in Epi-iPS cells. They produced high-contribution chimaeras that yielded germline transmission. These properties were maintained after Cre-mediated deletion of the Klf4 transgene, formally demonstrating complete and stable reprogramming of developmental phenotype. Thus, re-expression of Klf4 in an appropriate environment can regenerate the naïve <span class="hlt">ground</span> <span class="hlt">state</span> from EpiSCs. Reprogramming is dependent on suppression of extrinsic growth factor stimuli and proceeds to completion in less than 1% of cells. This substantiates the argument that EpiSCs are developmentally, epigenetically and functionally differentiated from ES cells. However, because a single transgene is the minimum requirement to attain the <span class="hlt">ground</span> <span class="hlt">state</span>, EpiSCs offer an attractive opportunity for screening for unknown components of the reprogramming process. PMID:19224983</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960025079','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960025079"><span>Quantum Cohesion Oscillation of Electron <span class="hlt">Ground</span> <span class="hlt">State</span> in Low Temperature Laser Plasma</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhao, Qingxun; Zhang, Ping; Dong, Lifang; Zhang, Kaixi</p> <p>1996-01-01</p> <p>The development of radically new technological and economically efficient methods for obtaining chemical products and for producing new materials with specific properties requires the study of physical and chemical processes proceeding at temperature of 10(exp 3) to 10(exp 4) K, temperature range of low temperature plasma. In our paper, by means of Wigner matrix of quantum statistical theory, a formula is derived for the <span class="hlt">energy</span> of quantum coherent oscillation of electron <span class="hlt">ground</span> <span class="hlt">state</span> in laser plasma at low temperature. The collective behavior would be important in ion and ion-molecule reactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMP....57j1505Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMP....57j1505Z"><span>Existence of <span class="hlt">ground</span> <span class="hlt">state</span> solutions to a generalized quasilinear Schrödinger-Maxwell system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Xiaoli; Li, Fuyi; Liang, Zhanping</p> <p>2016-10-01</p> <p>In this paper, a class of generalized quasilinear Schrödinger-Maxwell systems is considered. Via the mountain pass theorem, we conclude the existence of positive <span class="hlt">ground</span> <span class="hlt">state</span> solutions when the potential may vanish at infinity and the nonlinear term has a quasicritical growth. During this process, we use the Coulomb <span class="hlt">energy</span> studied by Ruiz [Arch. Ration. Mech. Anal. 198(1), 349-368 (2010)] and establish a convergency theorem to overcome the lack of compactness caused by the potential which may vanish at infinity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6098615','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6098615"><span>Search for <span class="hlt">ground</span> <span class="hlt">state</span> proton emission from sup 65 As and sup 69 Br</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Robertson, J.D.; Reiff, J.E.; Lang, T.F.; Moltz, D.M.; Cerny, J. Nuclear Science Division, Lawrence Berkeley Laboratory, University of California, Berkeley, CA )</p> <p>1990-11-01</p> <p>The <span class="hlt">ground</span> <span class="hlt">state</span> proton decays of {sup 65}As and {sup 69}Br have been searched for in {sup 28}Si and {sup 32}S bombardments of a natural calcium target. These studies employed a newly developed rapidly rotating recoil-catcher wheel and a low-<span class="hlt">energy</span> particle-identification telescope. No proton groups that could be assigned to either of these nuclides were observed. The minimum detectable limits indicate that {sup 65}As and {sup 69}Br either decay predominantly by beta emission or have half-lives less than 100 {mu}s. The overall evidence strongly indicates that {sup 65}As predominantly beta decays.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20718364','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20718364"><span>Excitations of {sup 1}P levels of zinc by electron impact on the <span class="hlt">ground</span> <span class="hlt">state</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fursa, Dmitry V.; Bray, Igor; Panajotovic, R.; Sevic, D.; Pejcev, V.; Marinkovic, B.P.; Filipovic, D.M.</p> <p>2005-07-15</p> <p>We present results of a joint theoretical and experimental investigation of electron scattering from the 4s{sup 2} {sup 1}S <span class="hlt">ground</span> <span class="hlt">state</span> of zinc. The 4s4p {sup 1}P{sup o} and 4s5p {sup 1}P{sup o} differential cross sections were measured at scattering angles between 10 degree sign and 150 degree sign and electron-<span class="hlt">energies</span> of 15, 20, 25, 40, and 60 eV. Corresponding convergent close-coupling calculations have been performed and are compared with experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26244376','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26244376"><span>Tetraphenylhexaazaanthracenes: 16π Weakly Antiaromatic Species with Singlet <span class="hlt">Ground</span> <span class="hlt">States</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Constantinides, Christos P; Zissimou, Georgia A; Berezin, Andrey A; Ioannou, Theodosia A; Manoli, Maria; Tsokkou, Demetra; Theodorou, Eleni; Hayes, Sophia C; Koutentis, Panayiotis A</p> <p>2015-08-21</p> <p>Tetraphenylhexaazaanthracene, TPHA-1, is a fluorescent zwitterionic biscyanine with a closed-shell singlet <span class="hlt">ground</span> <span class="hlt">state</span>. TPHA-1 overcomes its weak 16π antiaromaticity by partitioning its π system into 6π positive and 10π negative cyanines. The synthesis of TPHA-1 is low yielding and accompanied by two analogous TPHA isomers: the deep red, non-charge-separated, quinoidal TPHA-2, and the deep green TPHA-3 that partitions into two equal but oppositely charged 8π cyanines. The three TPHA isomers are compared.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhLB..766..334D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhLB..766..334D"><span>Triaxiality near the 110Ru <span class="hlt">ground</span> <span class="hlt">state</span> from Coulomb excitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Doherty, D. T.; Allmond, J. M.; Janssens, R. V. F.; Korten, W.; Zhu, S.; Zielińska, M.; Radford, D. C.; Ayangeakaa, A. D.; Bucher, B.; Batchelder, J. C.; Beausang, C. W.; Campbell, C.; Carpenter, M. P.; Cline, D.; Crawford, H. L.; David, H. M.; Delaroche, J. P.; Dickerson, C.; Fallon, P.; Galindo-Uribarri, A.; Kondev, F. G.; Harker, J. L.; Hayes, A. B.; Hendricks, M.; Humby, P.; Girod, M.; Gross, C. J.; Klintefjord, M.; Kolos, K.; Lane, G. J.; Lauritsen, T.; Libert, J.; Macchiavelli, A. O.; Napiorkowski, P. J.; Padilla-Rodal, E.; Pardo, R. C.; Reviol, W.; Sarantites, D. G.; Savard, G.; Seweryniak, D.; Srebrny, J.; Varner, R.; Vondrasek, R.; Wiens, A.; Wilson, E.; Wood, J. L.; Wu, C. Y.</p> <p>2017-03-01</p> <p>A multi-step Coulomb excitation measurement with the GRETINA and CHICO2 detector arrays was carried out with a 430-MeV beam of the neutron-rich 110Ru (t1/2 = 12 s) isotope produced at the CARIBU facility. This represents the first successful measurement following the post-acceleration of an unstable isotope of a refractory element. The reduced transition probabilities obtained for levels near the <span class="hlt">ground</span> <span class="hlt">state</span> provide strong evidence for a triaxial shape; a conclusion confirmed by comparisons with the results of beyond-mean-field and triaxial rotor model calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720050058&hterms=cesium+sodium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcesium%2Bsodium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720050058&hterms=cesium+sodium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcesium%2Bsodium"><span>Photoabsorption by <span class="hlt">ground-state</span> alkali-metal atoms.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weisheit, J. C.</p> <p>1972-01-01</p> <p>Principal-series oscillator strengths and <span class="hlt">ground-state</span> photoionization cross sections are computed for sodium, potassium, rubidium, and cesium. The degree of polarization of the photoelectrons is also predicted for each atom. The core-polarization correction to the dipole transition moment is included in all of the calculations, and the spin-orbit perturbation of valence-p-electron orbitals is included in the calculations of the Rb and Cs oscillator strengths and of all the photoionization cross sections. The results are compared with recent measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1343163-triaxiality-near-ground-state-from-coulomb-excitation','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1343163-triaxiality-near-ground-state-from-coulomb-excitation"><span>Triaxiality near the 110Ru <span class="hlt">ground</span> <span class="hlt">state</span> from Coulomb excitation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Doherty, D. T.; Allmond, James M.; Janssens, R. V. F.; ...</p> <p>2017-01-20</p> <p>A multi-step Coulomb excitation measurement with the GRETINA and CHICO2 detector arrays was carried out with a 430-MeV beam of the neutron-rich 110Ru (t1/2 = 12 s) isotope produced at the CARIBU facility. This represents the first successful measurement following the post-acceleration of an unstable isotope of a refractory element. The reduced transition probabilities obtained for levels near the <span class="hlt">ground</span> <span class="hlt">state</span> provide strong evidence for a triaxial shape; a conclusion confirmed by comparisons with the results of beyond-mean-field and triaxial rotor model calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014CMaPh.329..959S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014CMaPh.329..959S"><span>Lee-Yang Polynomials and <span class="hlt">Ground</span> <span class="hlt">States</span> of Spin Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Slawny, Joseph</p> <p>2014-08-01</p> <p>We obtain two kinds of results on the region in the space of the interactions of lattice systems where the Lee-Yang property holds (LY domain). First we show that the LY domain is related to interactions with exactly two <span class="hlt">ground</span> <span class="hlt">states</span>. Then we give a description of the full LY domain of an extended "plaquette model" analyzed by Lebowitz and Ruelle (Commun Math Phys 304:711-722, <CitationRef CitationID="CR8">2011). This allows us to prove a permanence property of the system, which we conjecture to hold in general.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhSS...58.1834B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhSS...58.1834B"><span>The <span class="hlt">ground</span> <span class="hlt">state</span> of the Frenkel-Kontorova model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Babushkin, A. Yu.; Abkaryan, A. K.; Dobronets, B. S.; Krasikov, V. S.; Filonov, A. N.</p> <p>2016-09-01</p> <p>The continual approximation of the <span class="hlt">ground</span> <span class="hlt">state</span> of the discrete Frenkel-Kontorova model is tested using a symmetric algorithm of numerical simulation. A "kaleidoscope effect" is found, which means that the curves representing the dependences of the relative extension of an N-atom chain vary periodically with increasing N. Stairs of structural transitions for N ≫ 1 are analyzed by the channel selection method with the approximation N = ∞. Images of commensurable and incommensurable structures are constructed. The commensurable-incommensurable phase transitions are stepwise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...593A..56S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...593A..56S"><span>Laboratory rotational <span class="hlt">ground</span> <span class="hlt">state</span> transitions of NH3D+ and CF+</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stoffels, A.; Kluge, L.; Schlemmer, S.; Brünken, S.</p> <p>2016-09-01</p> <p>Aims: This paper reports accurate laboratory frequencies of the rotational <span class="hlt">ground</span> <span class="hlt">state</span> transitions of two astronomically relevant molecular ions, NH3D+ and CF+. Methods: Spectra in the millimetre-wave <span class="hlt">band</span> were recorded by the method of rotational state-selective attachment of He atoms to the molecular ions stored and cooled in a cryogenic ion trap held at 4 K. The lowest rotational transition in the A state (ortho state) of NH3D+ (JK = 10-00), and the two hyperfine components of the <span class="hlt">ground</span> <span class="hlt">state</span> transition of CF+ (J = 1-0) were measured with a relative precision better than 10-7. Results: For both target ions, the experimental transition frequencies agree with recent observations of the same lines in different astronomical environments. In the case of NH3D+ the high-accuracy laboratory measurements lend support to its tentative identification in the interstellar medium. For CF+ the experimentally determined hyperfine splitting confirms previous quantum-chemical calculations and the intrinsic spectroscopic nature of a double-peaked line profile observed in the J = 1-0 transition towards the Horsehead photon-dominated region (PDR).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/564930','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/564930"><span>Spins, Parity, Excitation <span class="hlt">Energies</span>, and Octupole Structure of an Excited Superdeformed <span class="hlt">Band</span> in {sup 194}Hg and Implications for Identical <span class="hlt">Bands</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hackman, G.; Khoo, T.L.; Carpenter, M.P.; Lauritsen, T.; Calderin, I.J.; Janssens, R.V.; Ackermann, D.; Ahmad, I.; Agarwala, S.; Blumenthal, D.J.; Fischer, S.M.; Nisius, D.; Reiter, P.; Young, J.; Amro, H.; Lopez-Martens, A.; Hannachi, F.; Korichi, A.; Amro, H.; Moore, E.F.; Lee, I.Y.; Macchiavelli, A.O.; Do Nakatsukasa, T.</p> <p>1997-11-01</p> <p>An excited superdeformed <span class="hlt">band</span> in {sup 194}Hg , observed to decay directly to both normal-deformed and superdeformed yrast states, is proposed to be a K{sup {pi}}=2{sup {minus}} octupole vibrational <span class="hlt">band</span>, based on its excitation <span class="hlt">energies</span>, spins, and likely parity. The transition <span class="hlt">energies</span> are identical to those of the yrast superdeformed <span class="hlt">band</span> in {sup 192}Hg , but originate from levels with different spins and parities. The evolution of transition <span class="hlt">energies</span> with spin suggests that cancellations between pairing and particle alignment are partly responsible for the identical transition <span class="hlt">energies</span>. {copyright} {ital 1997} {ital The American Physical Society}</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1299786','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1299786"><span>Oligomeric state of human erythrocyte <span class="hlt">band</span> 3 measured by fluorescence resonance <span class="hlt">energy</span> homotransfer.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Blackman, S M; Piston, D W; Beth, A H</p> <p>1998-01-01</p> <p>The oligomeric state of the erythrocyte anion exchange protein, <span class="hlt">band</span> 3, has been assayed by resonance <span class="hlt">energy</span> homotransfer. Homotransfer between oligomeric subunits, labeled with eosin-5-maleimide at Lys430 in the transmembrane domain, has been demonstrated by steady-state and time-resolved fluorescence spectroscopy, and is readily observed by its depolarization of the eosin fluorescence. Polarized fluorescence measurements of HPLC-purified <span class="hlt">band</span> 3 oligomers indicate that eosin homotransfer increases progressively with increasing species size. This shows that homotransfer also occurs between labeled <span class="hlt">band</span> 3 dimers as well as within the dimers, making fluorescence anisotropy measurements sensitive to <span class="hlt">band</span> 3 self-association. Treatment of ghost membranes with either Zn2+ or melittin, agents that cluster <span class="hlt">band</span> 3, significantly decreases the anisotropy as a result of the increased homotransfer within the <span class="hlt">band</span> 3 clusters. By comparison with the anisotropy of species of known oligomeric state, the anisotropy of erythrocyte ghost membranes at 37 degrees C is consistent with dimeric and/or tetrameric <span class="hlt">band</span> 3, and does not require postulation of a fraction of large clusters. Proteolytic removal of the cytoplasmic domain of <span class="hlt">band</span> 3, which significantly increases the rotational mobility of the transmembrane domain, does not affect its oligomeric state, as reported by eosin homotransfer. These results support a model in which interaction with the membrane skeleton restricts the mobility of <span class="hlt">band</span> 3 without significantly altering its self-association state. PMID:9675213</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015CoTPh..64..395Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015CoTPh..64..395Z"><span><span class="hlt">Energy</span> <span class="hlt">Band</span> and Josephson Dynamics of Spin-Orbit Coupled Bose-Einstein Condensates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Xin; Yu, Zi-Fa; Xue, Ju-Kui</p> <p>2015-10-01</p> <p>We theoretically investigate the <span class="hlt">energy</span> <span class="hlt">band</span> structure and Josephson dynamics of a spin-orbit coupled Bose-Einstein condensate in a double-well potential. We study the <span class="hlt">energy</span> <span class="hlt">band</span> structure and the corresponding tunneling dynamics of the system by properly adjusting the SO coupling, Raman coupling, Zeeman field and atomic interactions. The coupled effects of SO coupling, Raman coupling, Zeeman field and atomic interactions lead to the appearance of complex <span class="hlt">energy</span> <span class="hlt">band</span> structure including the loop structure. Particularly, the emergence of the loop structure in <span class="hlt">energy</span> <span class="hlt">band</span> also depends on SO coupling, Raman coupling, Zeeman field and atomic interactions. Correspondingly, the Josephson dynamics of the system are strongly related to the <span class="hlt">energy</span> <span class="hlt">band</span> structure. Especially, the emergence of the loop structure results in complex tunneling dynamics, including suppression-revival transitions and self-trapping of atoms transfer between two spin states and two wells. This engineering provides a possible means for studying <span class="hlt">energy</span> level and corresponding dynamics of two-species SO coupled BECs. Supported by the National Natural Science Foundation of China under Grant Nos. 11274255 and 11305132, by Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20136203110001, by the Natural Science Foundation of Gansu province under Grant No. 2011GS04358, and by Creation of Science and Technology of Northwest Normal University under Grant Nos. NWNU-KJCXGC-03-48, NWNU-LKQN-12-12</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JEMat..45.5040J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JEMat..45.5040J"><span>Strain-Induced <span class="hlt">Energy</span> <span class="hlt">Band</span> Gap Opening in Two-Dimensional Bilayered Silicon Film</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ji, Z.; Zhou, R.; Lew Yan Voon, L. C.; Zhuang, Y.</p> <p>2016-10-01</p> <p>This work presents a theoretical study of the structural and electronic properties of bilayered silicon film (BiSF) under in-plane biaxial strain/stress using density functional theory (DFT). Atomic structures of the two-dimensional (2-D) silicon films are optimized by using both the local-density approximation (LDA) and generalized gradient approximation (GGA). In the absence of strain/stress, five buckled hexagonal honeycomb structures of the BiSF with triangular lattice have been obtained as local <span class="hlt">energy</span> minima, and their structural stability has been verified. These structures present a Dirac-cone shaped <span class="hlt">energy</span> <span class="hlt">band</span> diagram with zero <span class="hlt">energy</span> <span class="hlt">band</span> gaps. Applying a tensile biaxial strain leads to a reduction of the buckling height. Atomically flat structures with zero buckling height have been observed when the AA-stacking structures are under a critical biaxial strain. Increase of the strain between 10.7% and 15.4% results in a <span class="hlt">band</span>-gap opening with a maximum <span class="hlt">energy</span> <span class="hlt">band</span> gap opening of ˜0.17 eV, obtained when a 14.3% strain is applied. <span class="hlt">Energy</span> <span class="hlt">band</span> diagrams, electron transmission efficiency, and the charge transport property are calculated. Additionally, an asymmetric energetically favorable atomic structure of BiSF shows a non-zero <span class="hlt">band</span> gap in the absence of strain/stress and a maximum <span class="hlt">band</span> gap of 0.15 eV as a -1.71% compressive strain is applied. Both tensile and compressive strain/stress can lead to a <span class="hlt">band</span> gap opening in the asymmetric structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhRvB..88r4104G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhRvB..88r4104G"><span>Theoretical study of the <span class="hlt">ground-state</span> structures and properties of niobium hydrides under pressure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Guoying; Hoffmann, Roald; Ashcroft, N. W.; Liu, Hanyu; Bergara, Aitor; Ma, Yanming</p> <p>2013-11-01</p> <p>As part of a search for enhanced superconductivity, we explore theoretically the <span class="hlt">ground-state</span> structures and properties of some hydrides of niobium over a range of pressures and particularly those with significant hydrogen content. A primary motivation originates with the observation that under normal conditions niobium is the element with the highest superconducting transition temperature (Tc), and moreover some of its compounds are metals again with very high Tc's. Accordingly, combinations of niobium with hydrogen, with its high dynamic <span class="hlt">energy</span> scale, are also of considerable interest. This is reinforced further by the suggestion that close to its insulator-metal transition, hydrogen may be induced to enter the metallic state somewhat prematurely by the addition of a relatively small concentration of a suitable transition metal. Here, the methods used correctly reproduce some <span class="hlt">ground-state</span> structures of niobium hydrides at even higher concentrations of niobium. Interestingly, the particular stoichiometries represented by NbH4 and NbH6 are stabilized at fairly low pressures when proton zero-point <span class="hlt">energies</span> are included. While no paired H2 units are found in any of the hydrides we have studied up to 400 GPa, we do find complex and interesting networks of hydrogens around the niobiums in high-pressure NbH6. The Nb-Nb separations in NbHn are consistently larger than those found in Nb metal at the respective pressures. The structures found in the <span class="hlt">ground</span> <span class="hlt">states</span> of the high hydrides, many of them metallic, suggest that the coordination number of hydrogens around each niobium atom grows approximately as 4n in NbHn (n = 1-4), and is as high as 20 in NbH6. NbH4 is found to be a plausible candidate to become a superconductor at high pressure, with an estimated Tc ˜ 38 K at 300 GPa.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22611408','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22611408"><span>First-principles determination of <span class="hlt">band-to-band</span> electronic transition <span class="hlt">energies</span> in cubic and hexagonal AlGaInN alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Freitas, F. L. Marques, M.; Teles, L. K.</p> <p>2016-08-15</p> <p>We provide approximate quasiparticle-corrected <span class="hlt">band</span> gap <span class="hlt">energies</span> for quaternary cubic and hexagonal Al{sub x}Ga{sub y}In{sub 1–x–y}N semiconductor alloys, employing a cluster expansion method to account for the inherent statistical disorder of the system. Calculated values are compared with photoluminescence measurements and discussed within the currently accepted model of emission in these materials by carrier localization. It is shown that bowing parameters are larger in the cubic phase, while the range of <span class="hlt">band</span> gap variation is bigger in the hexagonal one. Experimentally determined transition <span class="hlt">energies</span> are mostly consistent with <span class="hlt">band-to-band</span> excitations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013CoPhC.184..812C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013CoPhC.184..812C"><span>GSGPEs: A MATLAB code for computing the <span class="hlt">ground</span> <span class="hlt">state</span> of systems of Gross-Pitaevskii equations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Caliari, Marco; Rainer, Stefan</p> <p>2013-03-01</p> <p>GSGPEs is a Matlab/GNU Octave suite of programs for the computation of the <span class="hlt">ground</span> <span class="hlt">state</span> of systems of Gross-Pitaevskii equations. It can compute the <span class="hlt">ground</span> <span class="hlt">state</span> in the defocusing case, for any number of equations with harmonic or quasi-harmonic trapping potentials, in spatial dimension one, two or three. The computation is based on a spectral decomposition of the solution into Hermite functions and direct minimization of the <span class="hlt">energy</span> functional through a Newton-like method with an approximate line-search strategy. Catalogue identifier: AENT_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AENT_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1417 No. of bytes in distributed program, including test data, etc.: 13673 Distribution format: tar.gz Programming language: Matlab/GNU Octave. Computer: Any supporting Matlab/GNU Octave. Operating system: Any supporting Matlab/GNU Octave. RAM: About 100 MB for a single three-dimensional equation (test run output). Classification: 2.7, 4.9. Nature of problem: A system of Gross-Pitaevskii Equations (GPEs) is used to mathematically model a Bose-Einstein Condensate (BEC) for a mixture of different interacting atomic species. The equations can be used both to compute the <span class="hlt">ground</span> <span class="hlt">state</span> solution (i.e., the stationary order parameter that minimizes the <span class="hlt">energy</span> functional) and to simulate the dynamics. For particular shapes of the traps, three-dimensional BECs can be also simulated by lower dimensional GPEs. Solution method: The <span class="hlt">ground</span> <span class="hlt">state</span> of a system of Gross-Pitaevskii equations is computed through a spectral decomposition into Hermite functions and the direct minimization of the <span class="hlt">energy</span> functional. Running time: About 30 seconds for a single three-dimensional equation with d.o.f. 40 for each spatial direction (test run output).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPhL.111g1902Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhL.111g1902Z"><span>Tri-<span class="hlt">band</span> miniaturized wide-angle and polarization-insensitive metasurface for ambient <span class="hlt">energy</span> harvesting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Xuanming; Liu, Haixia; Li, Long</p> <p>2017-08-01</p> <p>In this paper, a tri-<span class="hlt">band</span> miniaturized wide-angle and polarization-insensitive metasurface is proposed as an ambient <span class="hlt">energy</span> collector. The metasurface is composed of a subwavelength butterfly-type closed-ring (BCR) array attached to a low-loss substrate with a metallic ground. Each unit cell of the <span class="hlt">energy</span> harvesting metasurface has only one harvesting port. Its <span class="hlt">energy</span> harvesting efficiency for different polarization and incident angles was analyzed, and the results show that the maximum harvesting efficiency is 90%, 83%, and 81% at the three frequency <span class="hlt">bands</span> of 0.9 GHz, 2.6 GHz, and 5.7 GHz, respectively. Moreover, a prototype of the 7 × 7 BCR metasurface harvesting array was fabricated and measured. The experimental results validate that the proposed metasurface performs well under transverse electric and transverse magnetic polarization and is suitable for wide-angle incident <span class="hlt">energy</span> harvesting in the three frequency <span class="hlt">bands</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27299467','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27299467"><span>Wedge <span class="hlt">energy</span> <span class="hlt">bands</span> of monolayer black phosphorus: a first-principles study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Minwoo; Bae, Hyeonhu; Lee, Seunghan; Yang, Li; Lee, Hoonkyung</p> <p>2016-08-03</p> <p>On the basis of first-principles calculations, we present intriguing electronic properties of halogen-striped functionalized monolayer black phosphorus. The halogen-striped monolayer black phosphorus is found to have a wedge <span class="hlt">energy</span> <span class="hlt">band</span> with the <span class="hlt">energy</span>-momentum relation of [Formula: see text] when the stripe-stripe distance is smaller than ~40 Å. Our tight-binding study shows that the wedge <span class="hlt">energy</span> <span class="hlt">band</span> occurs when 2-atom basis 1D lattices are periodically repeated aligned with each other in a 2D lattice. We also discuss the possible applications of this wedge <span class="hlt">energy</span> <span class="hlt">band</span> in electron supercollimation with high mobility or severely anisotropic electronic transport, which can be used for the development of optics-like nano-electronics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26172664','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26172664"><span><span class="hlt">Ground-state</span> statistics of directed polymers with heavy-tailed disorder.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gueudre, Thomas; Le Doussal, Pierre; Bouchaud, Jean-Philippe; Rosso, Alberto</p> <p>2015-06-01</p> <p>In this mostly numerical study, we reconsider the statistical properties of the <span class="hlt">ground</span> <span class="hlt">state</span> of a directed polymer in a d=1+1 "hilly" disorder landscape, i.e., when the quenched disorder has power-law tails. When disorder is Gaussian, the polymer minimizes its total <span class="hlt">energy</span> through a collective optimization, where the <span class="hlt">energy</span> of each visited site only weakly contributes to the total. Conversely, a hilly landscape forces the polymer to distort and explore a larger portion of space to reach some particularly deep <span class="hlt">energy</span> sites. As soon as the fifth moment of the disorder diverges, this mechanism radically changes the standard Kardar-Parisi-Zhang scaling behavior of the directed polymer, and new exponents prevail. After confirming again that the Flory argument accurately predicts these exponents in the tail-dominated phase, we investigate several other statistical features of the <span class="hlt">ground</span> <span class="hlt">state</span> that shed light on this unusual transition and on the accuracy of the Flory argument. We underline the theoretical challenge posed by this situation, which paradoxically becomes even more acute above the upper critical dimension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1185963','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1185963"><span>Magnetic <span class="hlt">ground</span> <span class="hlt">state</span> of semiconducting transition-metal trichalcogenide monolayers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sivadas, Nikhil; Daniels, Matthew W.; Swendsen, Robert H.; Okamoto, Satoshi; Xiao, Di</p> <p>2015-06-16</p> <p>Layered transition-metal trichalcogenides with the chemical formula ABX<sub>3</sub> have attracted recent interest as potential candidates for two-dimensional magnets. Using first-principles calculations within density functional theory, we investigate the magnetic <span class="hlt">ground</span> <span class="hlt">states</span> of monolayers of Mn- and Cr-based semiconducting trichalcogenides.We show that the second and third nearest-neighbor exchange interactions (J<sub>2</sub> and J<sub>3</sub>) between magnetic ions, which have been largely overlooked in previous theoretical studies, are crucial in determining the magnetic <span class="hlt">ground</span> <span class="hlt">state</span>. Specifically, we find that monolayer CrSiTe<sub>3</sub> is an antiferromagnet with a zigzag spin texture due to significant contribution from J<sub>3</sub>, whereas CrGeTe<sub>3</sub> is a ferromagnet with a Curie temperature of 106 K. Monolayers of Mn compounds (MnPS<sub>3</sub> and MnPSe<sub>3</sub>) always show antiferromagnetic N eel order. We identify the physical origin of various exchange interactions, and demonstrate that strain can be an effective knob for tuning the magnetic properties. Possible magnetic ordering in the bulk is also discussed. In conclusion, our study suggests that ABX<sub>3</sub> can be a promising platform to explore two-dimensional magnetic phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhRvA..88b2335K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhRvA..88b2335K"><span><span class="hlt">Ground</span> <span class="hlt">states</span> of fermionic lattice Hamiltonians with permutation symmetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kraus, Christina V.; Lewenstein, Maciej; Cirac, J. Ignacio</p> <p>2013-08-01</p> <p>We study the <span class="hlt">ground</span> <span class="hlt">states</span> of lattice Hamiltonians that are invariant under permutations, in the limit where the number of lattice sites N→∞. For spin systems, these are product states, a fact that follows directly from the quantum de Finetti theorem. For fermionic systems, however, the problem is very different, since mode operators acting on different sites do not commute, but anticommute. We construct a family of fermionic states, F, from which such <span class="hlt">ground</span> <span class="hlt">states</span> can be easily computed. They are characterized by few parameters whose number only depends on M, the number of modes per lattice site. We also give an explicit construction for M=1,2. In the first case, F is contained in the set of Gaussian states, whereas in the second it is not. Inspired by that construction, we build a set of fermionic variational wave functions, and apply it to the Fermi-Hubbard model in two spatial dimensions, obtaining results that go beyond the generalized Hartree-Fock theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1185963-magnetic-ground-state-semiconducting-transition-metal-trichalcogenide-monolayers','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1185963-magnetic-ground-state-semiconducting-transition-metal-trichalcogenide-monolayers"><span>Magnetic <span class="hlt">ground</span> <span class="hlt">state</span> of semiconducting transition-metal trichalcogenide monolayers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Sivadas, Nikhil; Daniels, Matthew W.; Swendsen, Robert H.; ...</p> <p>2015-06-16</p> <p>Layered transition-metal trichalcogenides with the chemical formula ABX3 have attracted recent interest as potential candidates for two-dimensional magnets. Using first-principles calculations within density functional theory, we investigate the magnetic <span class="hlt">ground</span> <span class="hlt">states</span> of monolayers of Mn- and Cr-based semiconducting trichalcogenides.We show that the second and third nearest-neighbor exchange interactions (J2 and J3) between magnetic ions, which have been largely overlooked in previous theoretical studies, are crucial in determining the magnetic <span class="hlt">ground</span> <span class="hlt">state</span>. Specifically, we find that monolayer CrSiTe3 is an antiferromagnet with a zigzag spin texture due to significant contribution from J3, whereas CrGeTe3 is a ferromagnet with a Curie temperaturemore » of 106 K. Monolayers of Mn compounds (MnPS3 and MnPSe3) always show antiferromagnetic N eel order. We identify the physical origin of various exchange interactions, and demonstrate that strain can be an effective knob for tuning the magnetic properties. Possible magnetic ordering in the bulk is also discussed. In conclusion, our study suggests that ABX3 can be a promising platform to explore two-dimensional magnetic phenomena.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20778798','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20778798"><span>Nuclear Magnetic Moment of the {sup 57}Cu <span class="hlt">Ground</span> <span class="hlt">State</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Minamisono, K.; Mertzimekis, T.J.; Pereira, J.; Mantica, P.F.; Pinter, J.S.; Stoker, J.B.; Tomlin, B.E.; Weerasiri, R.R.; Davies, A.D.; Hass, M.; Rogers, W.F.</p> <p>2006-03-17</p> <p>The nuclear magnetic moment of the <span class="hlt">ground</span> <span class="hlt">state</span> of {sup 57}Cu(I{sup {pi}}=3/2{sup -},T{sub 1/2}=196.3 ms) has been measured to be vertical bar {mu}({sup 57}Cu) vertical bar =(2.00{+-}0.05){mu}{sub N} using the {beta}-NMR technique. Together with the known magnetic moment of the mirror partner {sup 57}Ni, the spin expectation value was extracted as <{sigma}{sigma}{sub z}>=-0.78{+-}0.13. This is the heaviest isospin T=1/2 mirror pair above the {sup 40}Ca region for which both <span class="hlt">ground</span> <span class="hlt">state</span> magnetic moments have been determined. The discrepancy between the present results and shell-model calculations in the full fp shell giving {mu}({sup 57}Cu){approx}2.4{mu}{sub N} and <{sigma}{sigma}{sub z}>{approx}0.5 implies significant shell breaking at {sup 56}Ni with the neutron number N=28.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhRvE..70e1913L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhRvE..70e1913L"><span>DNA-DNA interaction beyond the <span class="hlt">ground</span> <span class="hlt">state</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, D. J.; Wynveen, A.; Kornyshev, A. A.</p> <p>2004-11-01</p> <p>The electrostatic interaction potential between DNA duplexes in solution is a basis for the statistical mechanics of columnar DNA assemblies. It may also play an important role in recombination of homologous genes. We develop a theory of this interaction that includes thermal torsional fluctuations of DNA using field-theoretical methods and Monte Carlo simulations. The theory extends and rationalizes the earlier suggested variational approach which was developed in the context of a <span class="hlt">ground</span> <span class="hlt">state</span> theory of interaction of nonhomologous duplexes. It shows that the heuristic variational theory is equivalent to the Hartree self-consistent field approximation. By comparison of the Hartree approximation with an exact solution based on the QM analogy of path integrals, as well as Monte Carlo simulations, we show that this easily analytically-tractable approximation works very well in most cases. Thermal fluctuations do not remove the ability of DNA molecules to attract each other at favorable azimuthal conformations, neither do they wash out the possibility of electrostatic “snap-shot” recognition of homologous sequences, considered earlier on the basis of <span class="hlt">ground</span> <span class="hlt">state</span> calculations. At short distances DNA molecules undergo a “torsional alignment transition,” which is first order for nonhomologous DNA and weaker order for homologous sequences.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007APS..MAR.R1020H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007APS..MAR.R1020H"><span>On the nature of the oligoacene <span class="hlt">ground</span> <span class="hlt">state</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hachmann, Johannes; Dorando, Jonathan; Aviles, Michael; Kin-Lic Chan, Garnet</p> <p>2007-03-01</p> <p>The nature of the oligoacene <span class="hlt">ground</span> <span class="hlt">state</span> - its spin, singlet-triplet gap, and diradical character as a function of chain-length - is a question of ongoing theoretical and experimental interest with notable technological implications. Previous computational studies have given inconclusive answers to this challenging electronic structure problem (see e.g. [1]). In the present study we exploit the capabilities of the local ab initio Density Matrix Renormalization Group (DMRG) [2], which allows the numerically exact (FCI) solution of the Schr"odinger equation in a chosen 1-particle basis and active space for quasi-one-dimensional systems. We compute the singlet-triplet gap from first principles as a function of system length ranging from naphthalene to tetradecacene, correlating the full π-space (i.e. up to 58 electrons in 58 orbitals) and converging the results to a few μEh accuracy [3]. In order to study the diradical nature of the oligoacene <span class="hlt">ground</span> <span class="hlt">state</span> we calculate expectation values over different diradical occupation and pair-correlation operators. Furthermore we study the natural orbitals and their occupation. [1] Bendikov, Duong, Starkey, Houk, Carter, Wudl, JACS 126 (2004), 7416. [2] Hachmann, Cardoen, Chan, JCP 125 (2006), 144101. [3] Hachmann, Dorando, Avil'es, Chan, in preparation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvB..91w5425S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvB..91w5425S"><span>Magnetic <span class="hlt">ground</span> <span class="hlt">state</span> of semiconducting transition-metal trichalcogenide monolayers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sivadas, Nikhil; Daniels, Matthew W.; Swendsen, Robert H.; Okamoto, Satoshi; Xiao, Di</p> <p>2015-06-01</p> <p>Layered transition-metal trichalcogenides with the chemical formula A B X3 have attracted recent interest as potential candidates for two-dimensional magnets. Using first-principles calculations within density functional theory, we investigate the magnetic <span class="hlt">ground</span> <span class="hlt">states</span> of monolayers of Mn- and Cr-based semiconducting trichalcogenides. We show that the second and third nearest-neighbor exchange interactions (J2 and J3) between magnetic ions, which have been largely overlooked in previous theoretical studies, are crucial in determining the magnetic <span class="hlt">ground</span> <span class="hlt">state</span>. Specifically, we find that monolayer CrSiTe3 is an antiferromagnet with a zigzag spin texture due to significant contribution from J3, whereas CrGeTe3 is a ferromagnet with a Curie temperature of 106 K. Monolayers of Mn compounds (MnPS3 and MnPSe3) always show antiferromagnetic Néel order. We identify the physical origin of various exchange interactions, and demonstrate that strain can be an effective knob for tuning the magnetic properties. Possible magnetic ordering in the bulk is also discussed. Our study suggests that A B X3 can be a promising platform to explore two-dimensional magnetic phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1236683-valence-fluctuating-ground-state-plutonium','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1236683-valence-fluctuating-ground-state-plutonium"><span>The valence-fluctuating <span class="hlt">ground</span> <span class="hlt">state</span> of plutonium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Janoschek, Marc; Das, Pinaki; Chakrabarti, Bismayan; ...</p> <p>2015-07-10</p> <p>A central issue in material science is to obtain understanding of the electronic correlations that control complex materials. Such electronic correlations frequently arise because of the competition of localized and itinerant electronic degrees of freedom. Although the respective limits of well-localized or entirely itinerant <span class="hlt">ground</span> <span class="hlt">states</span> are well understood, the intermediate regime that controls the functional properties of complex materials continues to challenge theoretical understanding. We have used neutron spectroscopy to investigate plutonium, which is a prototypical material at the brink between bonding and nonbonding configurations. In addition, our study reveals that the <span class="hlt">ground</span> <span class="hlt">state</span> of plutonium is governed bymore » valence fluctuations, that is, a quantum mechanical superposition of localized and itinerant electronic configurations as recently predicted by dynamical mean field theory. Our results not only resolve the long-standing controversy between experiment and theory on plutonium’s magnetism but also suggest an improved understanding of the effects of such electronic dichotomy in complex materials.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15600662','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15600662"><span>DNA-DNA interaction beyond the <span class="hlt">ground</span> <span class="hlt">state</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, D J; Wynveen, A; Kornyshev, A A</p> <p>2004-11-01</p> <p>The electrostatic interaction potential between DNA duplexes in solution is a basis for the statistical mechanics of columnar DNA assemblies. It may also play an important role in recombination of homologous genes. We develop a theory of this interaction that includes thermal torsional fluctuations of DNA using field-theoretical methods and Monte Carlo simulations. The theory extends and rationalizes the earlier suggested variational approach which was developed in the context of a <span class="hlt">ground</span> <span class="hlt">state</span> theory of interaction of nonhomologous duplexes. It shows that the heuristic variational theory is equivalent to the Hartree self-consistent field approximation. By comparison of the Hartree approximation with an exact solution based on the QM analogy of path integrals, as well as Monte Carlo simulations, we show that this easily analytically-tractable approximation works very well in most cases. Thermal fluctuations do not remove the ability of DNA molecules to attract each other at favorable azimuthal conformations, neither do they wash out the possibility of electrostatic "snap-shot" recognition of homologous sequences, considered earlier on the basis of <span class="hlt">ground</span> <span class="hlt">state</span> calculations. At short distances DNA molecules undergo a "torsional alignment transition," which is first order for nonhomologous DNA and weaker order for homologous sequences.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JChPh.129m4705W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JChPh.129m4705W"><span>Au42: A possible <span class="hlt">ground-state</span> noble metallic nanotube</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Jing; Ning, Hua; Ma, Qing-Min; Liu, Ying; Li, You-Cheng</p> <p>2008-10-01</p> <p>A large hollow tubelike Au42 is predicted as a new <span class="hlt">ground-state</span> configuration based on the scalar relativistic density functional theory. The shape of this new Au42 cluster is similar to a (5,5) single-wall gold nanotube, the two ends of which are capped by half of a fullerenelike Au32. In the same way, a series of Aun (n =37,42,47,52,57,62,67,72,…, Δn =5) tubelike structures has been constructed. The highest occupied molecular orbital-lowest unoccupied molecular orbital gaps suggested a significant semiconductor-conductor alternation in n ɛ[32,47]. Similar to the predictions and speculation of Daedalus [D. E. H. Jones, New Sci. 32, 245 (1966); E. Osawa, Superaromaticity (Kagaku, Kyoto, 1970), Vol. 25, pp. 854-863; Z. Yoshida and E. Osawa, Aromaticity Chemical Monograph (Kagaku Dojin, Kyoto, Japan, 1971), Vol. 22, pp. 174-176; D. A. Bochvar and E. G. Gal'pern, Dokl. Akad. Nauk SSSR 209, 610 (1973)], here a large hollow <span class="hlt">ground-state</span> gold nanotube was predicted theoretically.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19045114','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19045114"><span>Au42: a possible <span class="hlt">ground-state</span> noble metallic nanotube.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Jing; Ning, Hua; Ma, Qing-Min; Liu, Ying; Li, You-Cheng</p> <p>2008-10-07</p> <p>A large hollow tubelike Au(42) is predicted as a new <span class="hlt">ground-state</span> configuration based on the scalar relativistic density functional theory. The shape of this new Au(42) cluster is similar to a (5,5) single-wall gold nanotube, the two ends of which are capped by half of a fullerenelike Au(32). In the same way, a series of Au(n) (n = 37, 42, 47, 52, 57, 62, 67, 72, ..., Delta n = 5) tubelike structures has been constructed. The highest occupied molecular orbital-lowest unoccupied molecular orbital gaps suggested a significant semiconductor-conductor alternation in n is an element of [32,47]. Similar to the predictions and speculation of Daedalus [D. E. H. Jones, New Sci. 32, 245 (1966); E. Osawa, Superaromaticity (Kagaku, Kyoto, 1970), Vol. 25, pp. 854-863; Z. Yoshida and E. Osawa, Aromaticity Chemical Monograph (Kagaku Dojin, Kyoto, Japan, 1971), Vol. 22, pp. 174-176; D. A. Bochvar and E. G. Gal'pern, Dokl. Akad. Nauk SSSR 209, 610 (1973)], here a large hollow <span class="hlt">ground-state</span> gold nanotube was predicted theoretically.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94a4514L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94a4514L"><span>Spatial competition of the <span class="hlt">ground</span> <span class="hlt">states</span> in 1111 iron pnictides</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lang, G.; Veyrat, L.; Gräfe, U.; Hammerath, F.; Paar, D.; Behr, G.; Wurmehl, S.; Grafe, H.-J.</p> <p>2016-07-01</p> <p>Using nuclear quadrupole resonance, the phase diagram of 1111 R FeAsO1 -xFx (R =La , Ce, Sm) iron pnictides is constructed as a function of the local charge distribution in the paramagnetic state, which features low-doping-like (LD-like) and high-doping-like (HD-like) regions. Compounds based on magnetic rare earths (Ce, Sm) display a unified behavior, and comparison with La-based compounds reveals the detrimental role of static iron 3 d magnetism on superconductivity, as well as a qualitatively different evolution of the latter at high doping. It is found that the LD-like regions fully account for the orthorhombicity of the system, and are thus the origin of any static iron magnetism. Orthorhombicity and static magnetism are not hindered by superconductivity but limited by dilution effects, in agreement with two-dimensional (2D) (respectively three-dimensional) nearest-neighbor square lattice site percolation when the rare earth is nonmagnetic (respectively magnetic). The LD-like regions are not intrinsically supportive of superconductivity, contrary to the HD-like regions, as evidenced by the well-defined Uemura relation between the superconducting transition temperature and the superfluid density when accounting for the proximity effect. This leads us to propose a complete description of the interplay of <span class="hlt">ground</span> <span class="hlt">states</span> in 1111 pnictides, where nanoscopic regions compete to establish the <span class="hlt">ground</span> <span class="hlt">state</span> through suppression of superconductivity by static magnetism, and extension of superconductivity by proximity effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvP...7c4022F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvP...7c4022F"><span>Origin of the Tetragonal <span class="hlt">Ground</span> <span class="hlt">State</span> of Heusler Compounds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Faleev, Sergey V.; Ferrante, Yari; Jeong, Jaewoo; Samant, Mahesh G.; Jones, Barbara; Parkin, Stuart S. P.</p> <p>2017-03-01</p> <p>We describe the general mechanism of tetragonal distortion in Heusler compounds X2Y Z . From 286 compounds studied using density-functional theory, 62% are found to be tetragonal at zero temperature. Such a large share of compounds with tetragonal distortions can be explained by the peak-and-valley character of the density of states (DOS) of these compounds in the cubic phase (arising from localized d <span class="hlt">bands</span> and van Hove singularities) in conjunction with a smooth shift of peaky DOS structure relative to the Fermi <span class="hlt">energy</span>, EF, when valence electrons are added to the system. A shift of the DOS in the Y or Z series leads to an alternation of stable and nonstable cubic phases that depends on the value of the DOS at EF in the cubic phase. Groups of compounds with a large share of tetragonal distortions are identified and explained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18465894','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18465894"><span>Electronic <span class="hlt">energy</span> <span class="hlt">band</span> structure of the double perovskite Ba2MnWO6.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fujioka, Yukari; Frantti, Johannes; Nieminen, Risto M</p> <p>2008-06-05</p> <p>The electronic and magnetic structures of the double perovskite oxide Ba 2MnWO6 (BMW) were determined by employing the density functional theory within the generalized gradient approximation (GGA) + U approach. BMW is considered a prototype double perovskite due to its high degree of B-site ordering and is a good case study for making a comparison between computations and experiments. By adjusting the U-parameter, the electronic <span class="hlt">energy</span> <span class="hlt">band</span> structure and magnetic properties, which were consistent with the experimental results, were obtained. These computations revealed that the valence <span class="hlt">bands</span> are mainly formed from Mn 3d and O 2p states, while the conduction <span class="hlt">bands</span> are derived from W 5d and O 2p states. The localized <span class="hlt">bands</span> composed from Mn 3d states are located in the bandgap. The results imply that the formation of polarons in the conduction <span class="hlt">band</span> initiate the resonance Raman modes observed as a series of equidistant peaks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhRvB..56.3664B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhRvB..56.3664B"><span>Exchange-correlation <span class="hlt">energy</span> of a hole gas including valence <span class="hlt">band</span> coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bobbert, P. A.; Wieldraaijer, H.; van der Weide, R.; Kemerink, M.; Koenraad, P. M.; Wolter, J. H.</p> <p>1997-08-01</p> <p>We have calculated an accurate exchange-correlation <span class="hlt">energy</span> of a hole gas, including the complexities related to the valence <span class="hlt">band</span> coupling as occurring in semiconductors like GaAs, but excluding the <span class="hlt">band</span> warping. A parametrization for the dependence on the density and the ratio between light- and heavy-hole masses is given. We apply our results to a hole gas in an AlxGa1-xAs/GaAs/AlxGa1-xAs quantum well and calculate the two-dimensional <span class="hlt">band</span> structure and the <span class="hlt">band</span>-gap renormalization. The inclusion of the valence <span class="hlt">band</span> coupling in the calculation of the exchange-correlation potentials for holes and electrons leads to a much better agreement between theoretical and experimental data than when it is omitted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JFuE...30...21A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JFuE...30...21A"><span>An Investigation for <span class="hlt">Ground</span> <span class="hlt">State</span> Features of Some Structural Fusion Materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aytekin, H.; Tel, E.; Baldik, R.; Aydin, A.</p> <p>2011-02-01</p> <p>Environmental concerns associated with fossil fuels are creating increased interest in alternative non-fossil <span class="hlt">energy</span> sources. Nuclear fusion can be one of the most attractive sources of <span class="hlt">energy</span> from the viewpoint of safety and minimal environmental impact. When considered in all <span class="hlt">energy</span> systems, the requirements for performance of structural materials in a fusion reactor first wall, blanket or diverter, are arguably more demanding or difficult than for other <span class="hlt">energy</span> system. The development of fusion materials for the safety of fusion power systems and understanding nuclear properties is important. In this paper, <span class="hlt">ground</span> <span class="hlt">state</span> properties for some structural fusion materials as 27Al, 51V, 52Cr, 55Mn, and 56Fe are investigated using Skyrme-Hartree-Fock method. The obtained results have been discussed and compared with the available experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OptMa..53..134K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OptMa..53..134K"><span>Effects of optical <span class="hlt">band</span> gap <span class="hlt">energy</span>, <span class="hlt">band</span> tail <span class="hlt">energy</span> and particle shape on photocatalytic activities of different ZnO nanostructures prepared by a hydrothermal method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klubnuan, Sarunya; Suwanboon, Sumetha; Amornpitoksuk, Pongsaton</p> <p>2016-03-01</p> <p>The dependence of the crystallite size and the <span class="hlt">band</span> tail <span class="hlt">energy</span> on the optical properties, particle shape and oxygen vacancy of different ZnO nanostructures to catalyse photocatalytic degradation was investigated. The ZnO nanoplatelets and mesh-like ZnO lamellae were synthesized from the PEO19-b-PPO3 modified zinc acetate dihydrate using aqueous KOH and CO(NH2)2 solutions, respectively via a hydrothermal method. The <span class="hlt">band</span> tail <span class="hlt">energy</span> of the ZnO nanostructures had more influence on the <span class="hlt">band</span> gap <span class="hlt">energy</span> than the crystallite size. The photocatalytic degradation of methylene blue increased as a function of the irradiation time, the amount of oxygen vacancy and the intensity of the (0 0 0 2) plane. The ZnO nanoplatelets exhibited a better photocatalytic degradation of methylene blue than the mesh-like ZnO lamellae due to the migration of the photoelectrons and holes to the (0 0 0 1) and (0 0 0 -1) planes, respectively under the internal electric field, that resulted in the enhancement of the photocatalytic activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21702555','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21702555"><span>High-resolution Fourier-transform infrared spectroscopy of the Coriolis coupled <span class="hlt">ground</span> <span class="hlt">state</span> and ν7 mode of ketenimine.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bane, Michael K; Robertson, Evan G; Thompson, Christopher D; Medcraft, Chris; Appadoo, Dominique R T; McNaughton, Don</p> <p>2011-06-21</p> <p>High resolution FTIR spectra of the short lived species ketenimine have been recorded in the regions 390-1300 cm(-1) and 20-110 cm(-1) using synchrotron radiation. Two thousand six hundred sixty transitions of the ν(7) <span class="hlt">band</span> centered at 693 cm(-1) and 126 far-IR rotational transitions have been assigned. Rotational and centrifugal distortion parameters for the ν(7) mode were determined and local Fermi and b-axis Coriolis interactions with 2ν(12) are treated. A further refinement of the <span class="hlt">ground</span> <span class="hlt">state</span>, ν(12) and ν(8) parameters was also achieved, including the treatment of previously unrecognized ac-axis and ab-axis second order perturbations to the <span class="hlt">ground</span> <span class="hlt">state</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhRvL.109f6404I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhRvL.109f6404I"><span>High-<span class="hlt">Energy</span> Anomaly in the <span class="hlt">Band</span> Dispersion of the Ruthenate Superconductor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iwasawa, H.; Yoshida, Y.; Hase, I.; Shimada, K.; Namatame, H.; Taniguchi, M.; Aiura, Y.</p> <p>2012-08-01</p> <p>We reveal a “high-<span class="hlt">energy</span> anomaly” (HEA) in the <span class="hlt">band</span> dispersion of the unconventional ruthenate superconductor Sr2RuO4, by means of high-resolution angle-resolved photoemission spectroscopy (ARPES) with tunable <span class="hlt">energy</span> and polarization of incident photons. This observation provides another class of correlated materials exhibiting this anomaly beyond high-Tc cuprates. We demonstrate that two distinct types of <span class="hlt">band</span> renormalization associated with and without the HEA occur as a natural consequence of the energetics in the bandwidth and the <span class="hlt">energy</span> scale of the HEA. Our results are well reproduced by a simple analytical form of the self-<span class="hlt">energy</span> based on the Fermi-liquid theory, indicating that the HEA exists at a characteristic <span class="hlt">energy</span> scale of the multielectron excitations. We propose that the HEA universally emerges if the systems have such a characteristic <span class="hlt">energy</span> scale inside of the bandwidth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20650240','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20650240"><span>Thermalization of fast cesium 5D{sub 3sol2} atoms in collisions with <span class="hlt">ground-state</span> cesium atoms</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marks, A.; Hickman, A. P.; Huennekens, J.; Streater, A. D.</p> <p>2005-01-01</p> <p>We have investigated collisions involving fast, excited Cs atoms produced by photodissociating Cs{sub 2} molecules with a pulsed dye laser. The velocities of the atoms in the 5D state formed by the process Cs{sub 2}(X {sup 1}{sigma}{sub g}{sup +})+({Dirac_h}/2{pi}){omega}{sub pump}{yields}Cs{sub 2}{sup *}{yields}Cs(5D)+Cs(6S) are much greater than typical thermal velocities associated with the cell temperature. Using a narrow-<span class="hlt">band</span> cw probe laser to observe the increased Doppler broadening of the 5D{sub 3/2}{yields}5F{sub 5/2} excitation line shape, we are able to monitor the time evolution of the velocity distribution of these 5D atoms. We analyze the data using a model that predicts the time-dependent excitation line shape of the fast atoms. Because the photons used to dissociate the molecules have a well-defined <span class="hlt">energy</span>, the velocity distribution of the excited atoms in the early time after they are produced can be fairly well determined. Over time, velocity-changing collisions with <span class="hlt">ground-state</span> Cs atoms cause the velocity distribution of excited atoms to approach the thermal limit. An analysis based on the strong-collision model leads to a prediction that the observed line shape at intermediate times will be a linear combination of contributions from distinct 'fast' and 'thermalized' atomic populations. By fitting our data to this model, a rate coefficient for velocity-changing collisions of fast Cs(5D{sub 3/2}) atoms with <span class="hlt">ground-state</span> Cs atoms has been determined. The result k{sub VCC}=(6.1{+-}1.2)x10{sup -10} cm{sup 3} s{sup -1} corresponds to an effective velocity-changing collision cross section of {sigma}{sub VCC}{sup Cs,eff}=(1.2{+-}0.2)x10{sup -14} cm{sup 2}.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhLB..756..283T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhLB..756..283T"><span>Hartree-Fock many-body perturbation theory for nuclear <span class="hlt">ground-states</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tichai, Alexander; Langhammer, Joachim; Binder, Sven; Roth, Robert</p> <p>2016-05-01</p> <p>We investigate the order-by-order convergence behavior of many-body perturbation theory (MBPT) as a simple and efficient tool to approximate the <span class="hlt">ground-state</span> <span class="hlt">energy</span> of closed-shell nuclei. To address the convergence properties directly, we explore perturbative corrections up to 30th order and highlight the role of the partitioning for convergence. The use of a simple Hartree-Fock solution for the unperturbed basis leads to a convergent MBPT series for soft interactions, in contrast to the divergent MBPT series obtained with a harmonic oscillator basis. For larger model spaces and heavier nuclei, where a direct high-order MBPT calculation is not feasible, we perform third-order calculations and compare to advanced ab initio coupled-cluster results for the same interactions and model spaces. We demonstrate that third-order MBPT provides <span class="hlt">ground-state</span> <span class="hlt">energies</span> for nuclei up into the tin isotopic chain in excellent agreement with the best available coupled-cluster calculations at a fraction of the computational cost.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23294447','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23294447"><span>Electronic absorption and <span class="hlt">ground</span> <span class="hlt">state</span> structure of carotenoid molecules.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mendes-Pinto, Maria M; Sansiaume, Elodie; Hashimoto, Hideki; Pascal, Andrew A; Gall, Andrew; Robert, Bruno</p> <p>2013-09-26</p> <p>Predicting the complete electronic structure of carotenoid molecules remains an extremely complex problem, particularly in anisotropic media such as proteins. In this paper, we address the electronic properties of nine relatively simple carotenoids by the combined use of electronic absorption and resonance Raman spectroscopies. Linear carotenoids exhibit an excellent correlation between (i) the inverse of their conjugation chain length N, (ii) the <span class="hlt">energy</span> of their S0 → S2 electronic transition, and (iii) the position of their ν1 Raman <span class="hlt">band</span> (corresponding to the stretching mode of their conjugated C═C bonds). For cyclic carotenoids such as β-carotene, this correlation is also observed between the latter two parameters (S0 → S2 <span class="hlt">energy</span> and ν1 frequency), whereas their "nominal" conjugation length N does not follow the same relationship. We conclude that β-carotene and cyclic carotenoids in general exhibit a shorter effective conjugation length than that expected from their chemical structure. In addition, the effect of solvent polarizability on these molecular parameters was investigated for four of the carotenoids used in this study. We demonstrate that resonance Raman spectroscopy can discriminate between the different effects underlying shifts in the S0 → S2 transition of carotenoid molecules.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1176927','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1176927"><span>Strategic <span class="hlt">Energy</span> Management Plan for the Santa Ynez <span class="hlt">Band</span> of Chumash Indians</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Davenport, Lars; Smythe, Louisa; Sarquilla, Lindsey; Ferguson, Kelly</p> <p>2015-03-27</p> <p>This plan outlines the Santa Ynez <span class="hlt">Band</span> of Chumash Indians’ comprehensive <span class="hlt">energy</span> management strategy including an assessment of current practices, a commitment to improving <span class="hlt">energy</span> performance and reducing overall <span class="hlt">energy</span> use, and recommended actions to achieve these goals. Vision Statement The primary objective of the Strategic <span class="hlt">Energy</span> Management Plan is to implement <span class="hlt">energy</span> efficiency, <span class="hlt">energy</span> security, conservation, education, and renewable <span class="hlt">energy</span> projects that align with the economic goals and cultural values of the community to improve the health and welfare of the tribe. The intended outcomes of implementing the <span class="hlt">energy</span> plan include job creation, capacity building, and reduced <span class="hlt">energy</span> costs for tribal community members, and tribal operations. By encouraging <span class="hlt">energy</span> independence and local power production the plan will promote self-sufficiency. Mission & Objectives The Strategic <span class="hlt">Energy</span> Plan will provide information and suggestions to guide tribal decision-making and provide a foundation for effective management of <span class="hlt">energy</span> resources within the Santa Ynez <span class="hlt">Band</span> of Chumash Indians (SYBCI) community. The objectives of developing this plan include; Assess current <span class="hlt">energy</span> demand and costs of all tribal enterprises, offices, and facilities; Provide a baseline assessment of the SYBCI’s <span class="hlt">energy</span> resources so that future progress can be clearly and consistently measured, and current usage better understood; Project future <span class="hlt">energy</span> demand; Establish a system for centralized, ongoing tracking and analysis of tribal <span class="hlt">energy</span> data that is applicable across sectors, facilities, and activities; Develop a unifying vision that is consistent with the tribe’s long-term cultural, social, environmental, and economic goals; Identify and evaluate the potential of opportunities for development of long-term, cost effective <span class="hlt">energy</span> sources, such as renewable <span class="hlt">energy</span>, <span class="hlt">energy</span> efficiency and conservation, and other feasible supply- and demand-side options; and Build the SYBCI’s capacity for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/530950','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/530950"><span>Including the relativistic kinetic <span class="hlt">energy</span> in a spline-augmented plane-wave <span class="hlt">band</span> calculation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fehrenbach, G.M.; Schmidt, G.</p> <p>1997-03-01</p> <p>The first-order relativistic correction to the kinetic <span class="hlt">energy</span> of an electron, the mass-velocity term, is not bounded from below. It can, therefore, not be used within a variational framework. To overcome this deficiency we developed a method to include the entire relativistic kinetic <span class="hlt">energy</span> {radical}(p{sup 2}c{sup 2}+m{sub 0}{sup 2}c{sup 4}){minus}m{sub 0}c{sup 2} in a spline-augmented plane-wave <span class="hlt">band</span> calculation. The first results for silver are quite promising, especially for d and p states: The analysis of the <span class="hlt">energies</span> of the core states as well as of the valence <span class="hlt">band</span> structure suggests that the <span class="hlt">energies</span> of d <span class="hlt">bands</span> are reproduced within 1 mRy. However, the combination of the relativistic kinetic <span class="hlt">energy</span> with the Darwin term leads to <span class="hlt">energies</span> which are too low for s-like valence states by 10 mRy. Therefore, the s and d valence <span class="hlt">band</span> complex is spread out and the Fermi level is lowered by the same amount as the s states. We expect to overcome these deficiencies in future investigations by using a alternative form of the relativistic potential correction along the lines proposed by Douglas and Kroll. {copyright} {ital 1997} {ital The American Physical Society}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JMoSp.252...41U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JMoSp.252...41U"><span>High-resolution infrared study of AsH 2D: The stretching fundamental <span class="hlt">bands</span> ν1/ ν5 and ν2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ulenikov, O. N.; Bekhtereva, E. S.; Yukhnik, Yu. B.; Vershinina, O. G.; Jerzembeck, W.; Bürger, H.</p> <p>2008-11-01</p> <p>High-resolution (ca. 0.0025 cm -1) Fourier transform infrared spectra of AsH 2D were recorded in the regions of the As-H and As-D stretching fundamental <span class="hlt">bands</span> ν1/ ν5 and ν2, respectively, and analyzed. Strong resonance interactions between the <span class="hlt">bands</span> ν1 and ν5, and also between the <span class="hlt">band</span> ν2 and the bending overtone <span class="hlt">band</span> 2 ν4 were established. From transitions observed in the ν1 and ν5 <span class="hlt">bands</span> <span class="hlt">ground</span> <span class="hlt">state</span> rotational <span class="hlt">energies</span> for larger values of rotational quantum numbers than previously available could be determined. Thereof improved <span class="hlt">ground</span> <span class="hlt">state</span> rotational parameters were derived. More than 3200 assigned transitions corresponding to 1059 upper state <span class="hlt">energy</span> levels which were almost equally distributed over the three stretching states were fitted with an rms-deviation of 0.00031 cm -1, which corresponds to experimental precision.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1079738','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1079738"><span>Negative Ion Photoelectron Spectroscopy Confirms the Prediction that (CO)5 and (CO)6 Each Has a Singlet <span class="hlt">Ground</span> <span class="hlt">State</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bao, Xiaoguang; Hrovat, David; Borden, Weston; Wang, Xue B.</p> <p>2013-03-20</p> <p>Cyclobutane-1,2,3,4-tetraone has been both predicted and found to have a triplet <span class="hlt">ground</span> <span class="hlt">state</span>, in which a b2g MO and an a2u MO is each singly occupied. In contrast, (CO)5 and (CO)6 have each been predicted to have a singlet <span class="hlt">ground</span> <span class="hlt">state</span>. This prediction has been tested by generating the (CO)5 - and (CO)6 - anions in the gas-phase by electrospray vaporization of solutions of, respectively, the croconate (CO)52- and rhodizonate (CO)62- dianions. The negative ion photoelectron (NIPE) spectra of the (CO)5•- radical anion give electron affinity (EA) = 3.830 eV and a singlet <span class="hlt">ground</span> <span class="hlt">state</span> for (CO)5, with the triplet higher in <span class="hlt">energy</span> by 0.850 eV (19.6 kcal/mol). The NIPE spectra of the (CO)6•- radical anion give EA = 3.785 eV and a singlet <span class="hlt">ground</span> <span class="hlt">state</span> for (CO)6, with the triplet higher in <span class="hlt">energy</span> by 0.915 eV (21.1 kcal/mol). (RO)CCSD(T)/aug-cc-pVTZ//(U)B3LYP/6-311+G(2df) calculations give EA values that are only ca. 1 kcal/mol lower than those measured and EST values that are only 2 - 3 kcal/mol higher than those obtained from the NIPE spectra. Thus, the calculations support the interpretations of the NIPE spectra and the finding, based on the spectra, that (CO)5 and (CO)6 both have a singlet <span class="hlt">ground</span> <span class="hlt">state</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94r4517B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94r4517B"><span>Multichiral <span class="hlt">ground</span> <span class="hlt">states</span> in mesoscopic p -wave superconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Becerra, V. Fernández; Milošević, M. V.</p> <p>2016-11-01</p> <p>Using Ginzburg-Landau formalism, we investigate the effect of confinement on the <span class="hlt">ground</span> <span class="hlt">state</span> of mesoscopic chiral p -wave superconductors in the absence of magnetic field. We reveal stable multichiral states with domain walls separating the regions with different chiralities, as well as monochiral states with spontaneous currents flowing along the edges. We show that multichiral states can exhibit identifying signatures in the spatial profile of the magnetic field if those are not screened by edge currents in the case of strong confinement. Such magnetic detection of domain walls in topological superconductors can serve as long-sought evidence of broken time-reversal symmetry. Furthermore, when applying electric current to mesoscopic p -wave samples, we found a hysteretic behavior in the current-voltage characteristic that distinguishes states with and without domain walls, thereby providing another useful hallmark for indirect confirmation of chiral p -wave superconductivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1032469','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1032469"><span>Tuning the magnetic <span class="hlt">ground</span> <span class="hlt">state</span> of a triangular lattice system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Garlea, Vasile O; Savici, Andrei T; Jin, Rongying</p> <p>2011-01-01</p> <p>The anisotropic triangular lattice of the crednerite system Cu(Mn$_{1-x}$Cu$_{x}$)O$_{2}$ is used as a basic model for studying the influence of spin disorder on the <span class="hlt">ground</span> <span class="hlt">state</span> properties of a two-dimensional frustrated antiferromagnet. Neutron diffraction measurements show that the undoped phase (x=0) undergoes a transition to antiferromagnetic long-range order that is stabilized by a frustration-relieving structural distortion. Small deviation from the stoichiometric composition alters the magnetoelastic characteristics and reduces the effective dimensionality of the magnetic lattice. Upon increasing the doping level, the interlayer coupling changes from antiferromagnetic to ferromagnetic, while the structural distortion is fully suppressed. Concomitantly, the long-range magnetic order is gradually transformed into a two-dimensional order.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMP....57d1505T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMP....57d1505T"><span><span class="hlt">Ground</span> <span class="hlt">state</span> solutions for semilinear time-harmonic Maxwell equations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tang, Xianhua; Qin, Dongdong</p> <p>2016-04-01</p> <p>This paper is concerned with the time-harmonic semilinear Maxwell equation: ∇ × (∇ × u) + λu = f(x, u) in Ω with the boundary condition ν × u = 0 on ∂Ω, where Ω ⊂ ℝ3 is a simply connected, smooth, bounded domain with connected boundary and ν : ∂Ω → ℝ3 is the exterior normal. Here ∇ × denotes the curl operator in ℝ3 and the boundary condition holds when Ω is surrounded by a perfect conductor. By using the generalized Nehari manifold method due to Szulkin and Weth [Handbook of Nonconvex Analysis and Applications (International Press, Somerville, 2010), pp. 597-632] and some new techniques, existence of <span class="hlt">ground</span> <span class="hlt">state</span> solutions for above equation is established under some generic conditions on f.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21301599','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21301599"><span>NEW <span class="hlt">GROUND-STATE</span> MEASUREMENTS OF ETHYL CYANIDE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Brauer, Carolyn S.; Pearson, John C.; Drouin, Brian J.; Yu, Shanshan</p> <p>2009-09-01</p> <p>The spectrum of ethyl cyanide, or propionitrile (CH{sub 3}CH{sub 2}CN), has been repeatedly observed in the interstellar medium with large column densities and surprisingly high temperatures in hot core sources. The construction of new, more sensitive, observatories accessing higher frequencies such as Herschel, ALMA, and SOFIA have made it important to extend the laboratory data for ethyl cyanide to coincide with the capabilities of the new instruments. We report extensions of the laboratory measurements of the rotational spectrum of ethyl cyanide in its ground vibrational state to 1.6 THz. A global analysis of the <span class="hlt">ground</span> <span class="hlt">state</span>, which includes all of the previous data and 3356 newly assigned transitions, has been fitted to within experimental error to J = 132, K = 36, using both Watson A-reduced and Watson S-reduced Hamiltonians.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95x5124T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95x5124T"><span>Wilson operator algebras and <span class="hlt">ground</span> <span class="hlt">states</span> of coupled BF theories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tiwari, Apoorv; Chen, Xiao; Ryu, Shinsei</p> <p>2017-06-01</p> <p>The multiflavor BF theories in (3+1) dimensions with cubic or quartic coupling are the simplest topological quantum field theories that can describe fractional braiding statistics between looplike topological excitations (three-loop or four-loop braiding statistics). In this paper, by canonically quantizing these theories, we study the algebra of Wilson loop and Wilson surface operators, and multiplets of <span class="hlt">ground</span> <span class="hlt">states</span> on the three-torus. In particular, by quantizing these coupled BF theories on the three-torus, we explicitly calculate the S and T matrices, which encode fractional braiding statistics and the topological spin of looplike excitations, respectively. In the coupled BF theories with cubic and quartic coupling, the Hopf link and Borromean ring of loop excitations, together with pointlike excitations, form composite particles.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhyE....2..453L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhyE....2..453L"><span>First resonant tunneling via a light-hole <span class="hlt">ground</span> <span class="hlt">state</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lampin, J. F.; Mollot, F.</p> <p>1998-07-01</p> <p>We report the demonstration of resonant tunneling of light-holes through an AlAs/GaAs 0.7P 0.3 double-barrier heterostructure. The tensile strain in the quantum well reverses the order of the light- and heavy-hole levels, the first light-hole level becoming the <span class="hlt">ground</span> <span class="hlt">state</span>. The I( V) characteristics are measured at different temperatures and compared to those of a standard AlAs/GaAs unstrained structure. The peak current density of the first light-hole resonance and its peak-to-valley current ratio are enhanced. They reach 28 A/cm 2 and 3.4 : 1 at 15 K. A negative differential resistance is observed up to 250 K.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARZ36011W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARZ36011W"><span>Absence of Quantum Time Crystals in <span class="hlt">Ground</span> <span class="hlt">States</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watanabe, Haruki; Oshikawa, Masaki</p> <p>2015-03-01</p> <p>In analogy with crystalline solids around us, Wilczek recently proposed the idea of ``time crystals'' as phases that spontaneously break the continuous time translation into a discrete subgroup. The proposal stimulated further studies and vigorous debates whether it can be realized in a physical system. However, a precise definition of the time crystal is needed to resolve the issue. Here we first present a definition of time crystals based on the time-dependent correlation functions of the order parameter. We then prove a no-go theorem that rules out the possibility of time crystals defined as such, in the <span class="hlt">ground</span> <span class="hlt">state</span> of a general Hamiltonian which consists of only short-range interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT.......139T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT.......139T"><span>Studies on the <span class="hlt">ground</span> <span class="hlt">state</span> entropy of the Potts antiferromagnet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsai, Shan-Ho</p> <p></p> <p>This dissertation reports recent results on the <span class="hlt">ground</span> <span class="hlt">state</span> degeneracy of the q-state antiferromagnetic Potts model. This model has a deep connection with graph theory in mathematics since the zero-temperature partition function of this model on a given lattice, or more generally on a graph G, is equal to the chromatic polynomial P(G, q), which expresses the number of ways of coloring the n vertices of a graph G using at most q colors such that no two adjacent vertices have the same color. The <span class="hlt">ground</span> <span class="hlt">state</span> degeneracy per site of the Potts antiferromagnet is given by W(\\{ G\\}, q) = limsb{n->infty}P(G, q)sp{1/n} (where \\{ G\\} denotes the limit as n-> infty of the family of n-vertex graphs of type G). Exact solutions for this problem are known in only very few special cases. We have obtained rigorous upper and lower bounds, large-q series expansions and Monte Carlo measurements of the <span class="hlt">ground</span> <span class="hlt">state</span> degeneracy W(Lambda,\\ q) of the antiferromagnetic Potts model on a number of two dimensional lattices. These bounds are shown to be very restrictive. In particular, the lower bounds coincide with many terms of the respective large-q series expansion and are very good approximations to the exact functions. Although q is an integer parameter in the definition of the initial model, it is instructive to generalize it to complex variable. We study the analytic structure of the function W(\\{ G\\}, q) in the complex q plane. We determine the exact locus {cal B} where W(\\{G\\}, q) is nonanalytic for a number of families of graphs G. We calculate chromatic polynomials on strip graphs of varying widths as a way of obtaining information on the two dimensional limit. For this purpose, we construct generating functions, which provide both the asymptotic limiting function W(\\{ G\\}, q) as well as chromatic polynomials for finite length strips. Exact calculation is presented for a number of families of strip graphs. Effects of different types of boundary conditions are examined</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26040716','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26040716"><span>Cloning and variation of <span class="hlt">ground</span> <span class="hlt">state</span> intestinal stem cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Xia; Yamamoto, Yusuke; Wilson, Lane H; Zhang, Ting; Howitt, Brooke E; Farrow, Melissa A; Kern, Florian; Ning, Gang; Hong, Yue; Khor, Chiea Chuen; Chevalier, Benoit; Bertrand, Denis; Wu, Lingyan; Nagarajan, Niranjan; Sylvester, Francisco A; Hyams, Jeffrey S; Devers, Thomas; Bronson, Roderick; Lacy, D Borden; Ho, Khek Yu; Crum, Christopher P; McKeon, Frank; Xian, Wa</p> <p>2015-06-11</p> <p>Stem cells of the gastrointestinal tract, pancreas, liver and other columnar epithelia collectively resist cloning in their elemental states. Here we demonstrate the cloning and propagation of highly clonogenic, '<span class="hlt">ground</span> <span class="hlt">state</span>' stem cells of the human intestine and colon. We show that derived stem-cell pedigrees sustain limited copy number and sequence variation despite extensive serial passaging and display exquisitely precise, cell-autonomous commitment to epithelial differentiation consistent with their origins along the intestinal tract. This developmentally patterned and epigenetically maintained commitment of stem cells is likely to enforce the functional specificity of the adult intestinal tract. Using clonally derived colonic epithelia, we show that toxins A or B of the enteric pathogen Clostridium difficile recapitulate the salient features of pseudomembranous colitis. The stability of the epigenetic commitment programs of these stem cells, coupled with their unlimited replicative expansion and maintained clonogenicity, suggests certain advantages for their use in disease modelling and regenerative medicine.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MPLB...3050224J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MPLB...3050224J"><span>Effective parameters in beam acoustic metamaterials based on <span class="hlt">energy</span> <span class="hlt">band</span> structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jing, Li; Wu, Jiu Hui; Guan, Dong; Hou, Mingming; Kuan, Lu; Shen, Li</p> <p>2016-07-01</p> <p>We present a method to calculate the effective material parameters of beam acoustic metamaterials. The effective material parameters of a periodic beam are calculated as an example. The dispersion relations and <span class="hlt">energy</span> <span class="hlt">band</span> structures of this beam are calculated. Subsequently, the effective material parameters of the beam are investigated by using the <span class="hlt">energy</span> <span class="hlt">band</span> structures. Then, the modal analysis and transmission properties of the beams with finite cells are simulated in order to confirm the correctness of effective approximation. The results show that the periodic beam can be equivalent to the homogeneous beam with dynamic effective material parameters in passband.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22741809','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22741809"><span><span class="hlt">Ground-state</span> thermodynamics of bistable redox-active donor-acceptor mechanically interlocked molecules.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fahrenbach, Albert C; Bruns, Carson J; Cao, Dennis; Stoddart, J Fraser</p> <p>2012-09-18</p> <p>Fashioned through billions of years of evolution, biological molecular machines, such as ATP synthase, myosin, and kinesin, use the intricate relative motions of their components to drive some of life's most essential processes. Having control over the motions in molecules is imperative for life to function, and many chemists have designed, synthesized, and investigated artificial molecular systems that also express controllable motions within molecules. Using bistable mechanically interlocked molecules (MIMs), based on donor-acceptor recognition motifs, we have sought to imitate the sophisticated nanoscale machines present in living systems. In this Account, we analyze the thermodynamic characteristics of a series of redox-switchable [2]rotaxanes and [2]catenanes. Control and understanding of the relative intramolecular movements of components in MIMs have been vital in the development of a variety of applications of these compounds ranging from molecular electronic devices to drug delivery systems. These bistable donor-acceptor MIMs undergo redox-activated switching between two isomeric states. Under ambient conditions, the dominant translational isomer, the <span class="hlt">ground-state</span> coconformation (GSCC), is in equilibrium with the less favored translational isomer, the metastable-state coconformation (MSCC). By manipulating the redox state of the recognition site associated with the GSCC, we can stimulate the relative movements of the components in these bistable MIMs. The thermodynamic parameters of model host-guest complexes provide a good starting point to rationalize the ratio of GSCC to MSCC at equilibrium. The bistable [2]rotaxanes show a strong correlation between the relative free <span class="hlt">energies</span> of model complexes and the <span class="hlt">ground-state</span> distribution constants (K(GS)). This relationship does not always hold for bistable [2]catenanes, most likely because of the additional steric and electronic constraints present when the two rings are mechanically interlocked with each other</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MS%26E...73a2100V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MS%26E...73a2100V"><span>Effect of Γ-X <span class="hlt">band</span> mixing on the donor binding <span class="hlt">energy</span> in a Quantum Wire</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vijaya Shanthi, R.; Jayakumar, K.; Nithiananthi, P.</p> <p>2015-02-01</p> <p>To invoke the technological applications of heterostructure semiconductors like Quantum Well (QW), Quantum Well Wire (QWW) and Quantum Dot (QD), it is important to understand the property of impurity <span class="hlt">energy</span> which is responsible for the peculiar electronic & optical behavior of the Low Dimensional Semiconductor Systems (LDSS). Application of hydrostatic pressure P>35kbar drastically alters the <span class="hlt">band</span> offsets leading to the crossover of Γ <span class="hlt">band</span> of the well & X <span class="hlt">band</span> of the barrier resulting in an indirect transition of the carrier and this effect has been studied experimentally and theoretically in a QW structure. In this paper, we have investigated the effect of Γ-X <span class="hlt">band</span> mixing due to the application of hydrostatic pressure in a GaAs/AlxGa1-xAs QWW system. The results are presented and discussed for various widths of the wire.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009IJMPB..23.5027E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009IJMPB..23.5027E"><span>First-Principles Study of Electronic Structure and <span class="hlt">Ground-State</span> Properties of Alkali-Metal Selenides and Tellurides (M2A) [M: Li, Na, k; a: Se, Te</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eithiraj, R. D.; Jaiganesh, G.; Kalpana, G.</p> <p></p> <p>First-principles calculations have been performed to investigate the electronic structure and <span class="hlt">ground-state</span> properties of alkali-metal Selenides (M2Se) and Tellurides (M2Te) [M: Li, Na, K] using the Tight-Binding Linear Muffin-Tin Orbital (TB-LMTO) method. The exchange correlation <span class="hlt">energy</span> is described within the local density approximation (LDA) using the von Barth and Hedin parameterization scheme. At ambient conditions, these compounds are found to crystallize in the face center cubic antifluorite (anti-CaF2-type) structure. <span class="hlt">Ground-state</span> properties such as total <span class="hlt">energy</span>, equilibrium lattice parameter, and bulk modulus are calculated for these compounds. The calculated equilibrium lattice parameter is in agreement with experimental result. From the electronic structure calculations, we find that Li2Se, Li2Te, K2Se, and K2Te are indirect bandgap semiconductors, whereas Na2Se and Na2Te are direct bandgap semiconductors. The present results are compared with the earlier results of series of alkali-metal sulfides (M2S) and alkali-metal oxides (M2O), allowing us to make predictions about the total <span class="hlt">energy</span>, bulk modulus, valence-<span class="hlt">band</span> width, and bandgap behavior of the rest of the alkali-chalcogenide crystals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994PhRvB..4916480G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994PhRvB..4916480G"><span>Density of states of the one-dimensional electron gas: Impurity levels, impurity <span class="hlt">bands</span>, and the <span class="hlt">band</span> tail</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gold, A.; Ghazali, A.</p> <p>1994-06-01</p> <p>The density of states of cylindrical quantum wires is calculated in the presence of charged impurities located in the center of the wire. A multiple-scattering approach (Klauder's fifth approximation), which represents a self-consistent t-matrix approximation, is used. For small impurity densities and in the weak screening limit the <span class="hlt">ground-state</span> impurity <span class="hlt">band</span> and four excited-state impurity <span class="hlt">bands</span> are obtained within our approach. We find good agreement between the numerically obtained spectral densities with the corresponding analytical spectral densities calculated with the single-impurity wave functions. The merging of impurity <span class="hlt">bands</span> is studied. For large impurity densities we obtain a <span class="hlt">band</span> tail. We present an analytical expression for the disorder-induced renormalized <span class="hlt">band</span>-edge <span class="hlt">energy</span> in the <span class="hlt">band</span>-tail regime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.6040E..1UW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.6040E..1UW"><span>Wavelet package frequency-<span class="hlt">band</span> <span class="hlt">energy</span> ratios of human EEG signals in sleeping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Li; Han, Qingpeng; Wang, Ping; Wen, Bangchun</p> <p>2005-12-01</p> <p>Human EEG (Electroencephalogram) signals, including 4 rhythms i.e. δ, θ, α, β, are typically nonlinear. They just coincide with different human sleeping states. The wavelet package decomposition and reconstruction techniques are firstly introduced in order to analyze the nonlinear EEG. A 6 level decomposition of EEG was achieved with "db20" as the mother wavelet, and the above 4 rhythms were combined with specialized 8 frequency sub-<span class="hlt">bands</span> obtained in wavelet package transform. The four frequency <span class="hlt">band</span> <span class="hlt">energy</span> ratios, with normalized values, were calculated from the reconstructed signals. These frequency <span class="hlt">band</span> <span class="hlt">energy</span> ratios are used as quantify estimation indexes for human sleeping states. The experimental results confirm the proposed method to be effective.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AIPA....2b2111C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AIPA....2b2111C"><span>Lateral <span class="hlt">energy</span> <span class="hlt">band</span> profile modulation in tunnel field effect transistors based on gate structure engineering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cui, Ning; Liang, Renrong; Wang, Jing; Xu, Jun</p> <p>2012-06-01</p> <p>Choosing novel materials and structures is important for enhancing the on-state current in tunnel field-effect transistors (TFETs). In this paper, we reveal that the on-state performance of TFETs is mainly determined by the <span class="hlt">energy</span> <span class="hlt">band</span> profile of the channel. According to this interpretation, we present a new concept of <span class="hlt">energy</span> <span class="hlt">band</span> profile modulation (BPM) achieved with gate structure engineering. It is believed that this approach can be used to suppress the ambipolar effect. Based on this method, a Si TFET device with a symmetrical tri-material-gate (TMG) structure is proposed. Two-dimensional numerical simulations demonstrated that the special <span class="hlt">band</span> profile in this device can boost on-state performance, and it also suppresses the off-state current induced by the ambipolar effect. These unique advantages are maintained over a wide range of gate lengths and supply voltages. The BPM concept can serve as a guideline for improving the performance of nanoscale TFET devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JChPh.142u4303V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JChPh.142u4303V"><span>Long-range interactions between polar bialkali <span class="hlt">ground-state</span> molecules in arbitrary vibrational levels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vexiau, R.; Lepers, M.; Aymar, M.; Bouloufa-Maafa, N.; Dulieu, O.</p> <p>2015-06-01</p> <p>We have calculated the isotropic C6 coefficients characterizing the long-range van der Waals interaction between two identical heteronuclear alkali-metal diatomic molecules in the same arbitrary vibrational level of their ground electronic state X1Σ+. We consider the ten species made up of 7Li, 23Na, 39K, 87Rb, and 133Cs. Following our previous work [Lepers et al., Phys. Rev. A 88, 032709 (2013)], we use the sum-over-state formula inherent to the second-order perturbation theory, composed of the contributions from the transitions within the <span class="hlt">ground</span> <span class="hlt">state</span> levels, from the transition between <span class="hlt">ground-state</span> and excited state levels, and from a crossed term. These calculations involve a combination of experimental and quantum-chemical data for potential <span class="hlt">energy</span> curves and transition dipole moments. We also investigate the case where the two molecules are in different vibrational levels and we show that the Moelwyn-Hughes approximation is valid provided that it is applied for each of the three contributions to the sum-over-state formula. Our results are particularly relevant in the context of inelastic and reactive collisions between ultracold bialkali molecules in deeply bound or in Feshbach levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21499780','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21499780"><span>Exploring <span class="hlt">ground</span> <span class="hlt">states</span> and excited states of spin-1 Bose-Einstein condensates by continuation methods</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, Jen-Hao; Chern, I-Liang; Wang Weichung</p> <p>2011-03-20</p> <p>A pseudo-arclength continuation method (PACM) is employed to compute the <span class="hlt">ground</span> <span class="hlt">state</span> and excited state solutions of spin-1 Bose-Einstein condensates (BEC). The BEC is governed by the time-independent coupled Gross-Pitaevskii equations (GPE) under the conservations of the mass and magnetization. The coupling constants that characterize the spin-independent and spin-exchange interactions are chosen as the continuation parameters. The continuation curve starts from a <span class="hlt">ground</span> <span class="hlt">state</span> or an excited state with very small coupling parameters. The proposed numerical schemes allow us to investigate the effect of the coupling constants and study the bifurcation diagrams of the time-independent coupled GPE. Numerical results on the wave functions and their corresponding <span class="hlt">energies</span> of spin-1 BEC with repulsive/attractive and ferromagnetic/antiferromagnetic interactions are presented. Furthermore, we reveal that the component separation and population transfer between the different hyperfine states can only occur in excited states due to the spin-exchange interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22255210','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22255210"><span>Thermodynamic <span class="hlt">ground</span> <span class="hlt">state</span> of MgB{sub 6} predicted from first principles structure search methods</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, Hui; LeBlanc, K. A.; Gao, Bo; Yao, Yansun</p> <p>2014-01-28</p> <p>Crystalline structures of magnesium hexaboride, MgB{sub 6}, were investigated using unbiased structure searching methods combined with first principles density functional calculations. An orthorhombic Cmcm structure was predicted as the thermodynamic <span class="hlt">ground</span> <span class="hlt">state</span> of MgB{sub 6}. The <span class="hlt">energy</span> of the Cmcm structure is significantly lower than the theoretical MgB{sub 6} models previously considered based on a primitive cubic arrangement of boron octahedra. The Cmcm structure is stable against the decomposition to elemental magnesium and boron solids at atmospheric pressure and high pressures up to 18.3 GPa. A unique feature of the predicted Cmcm structure is that the boron atoms are clustered into two forms: localized B{sub 6} octahedra and extended B{sub ∞} ribbons. Within the boron ribbons, the electrons are delocalized and this leads to a metallic <span class="hlt">ground</span> <span class="hlt">state</span> with vanished electric dipoles. The present prediction is in contrast to the previous proposal that the crystalline MgB{sub 6} maintains a semiconducting state with permanent dipole moments. MgB{sub 6} is estimated to have much weaker electron-phonon coupling compared with that of MgB{sub 2}, and therefore it is not expected to be able to sustain superconductivity at high temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22489682','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22489682"><span>Electron momentum spectroscopy of dimethyl ether taking account of nuclear dynamics in the electronic <span class="hlt">ground</span> <span class="hlt">state</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Morini, Filippo; Deleuze, Michael Simon; Watanabe, Noboru; Kojima, Masataka; Takahashi, Masahiko</p> <p>2015-10-07</p> <p>The influence of nuclear dynamics in the electronic <span class="hlt">ground</span> <span class="hlt">state</span> on the (e,2e) momentum profiles of dimethyl ether has been analyzed using the harmonic analytical quantum mechanical and Born-Oppenheimer molecular dynamics approaches. In spite of fundamental methodological differences, results obtained with both approaches consistently demonstrate that molecular vibrations in the electronic <span class="hlt">ground</span> <span class="hlt">state</span> have a most appreciable influence on the momentum profiles associated to the 2b{sub 1}, 6a{sub 1}, 4b{sub 2}, and 1a{sub 2} orbitals. Taking this influence into account considerably improves the agreement between theoretical and newly obtained experimental momentum profiles, with improved statistical accuracy. Both approaches point out in particular the most appreciable role which is played by a few specific molecular vibrations of A{sub 1}, B{sub 1}, and B{sub 2} symmetries, which correspond to C–H stretching and H–C–H bending modes. In line with the Herzberg-Teller principle, the influence of these molecular vibrations on the computed momentum profiles can be unraveled from considerations on the symmetry characteristics of orbitals and their <span class="hlt">energy</span> spacing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26450316','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26450316"><span>Electron momentum spectroscopy of dimethyl ether taking account of nuclear dynamics in the electronic <span class="hlt">ground</span> <span class="hlt">state</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Morini, Filippo; Watanabe, Noboru; Kojima, Masataka; Deleuze, Michael Simon; Takahashi, Masahiko</p> <p>2015-10-07</p> <p>The influence of nuclear dynamics in the electronic <span class="hlt">ground</span> <span class="hlt">state</span> on the (e,2e) momentum profiles of dimethyl ether has been analyzed using the harmonic analytical quantum mechanical and Born-Oppenheimer molecular dynamics approaches. In spite of fundamental methodological differences, results obtained with both approaches consistently demonstrate that molecular vibrations in the electronic <span class="hlt">ground</span> <span class="hlt">state</span> have a most appreciable influence on the momentum profiles associated to the 2b1, 6a1, 4b2, and 1a2 orbitals. Taking this influence into account considerably improves the agreement between theoretical and newly obtained experimental momentum profiles, with improved statistical accuracy. Both approaches point out in particular the most appreciable role which is played by a few specific molecular vibrations of A1, B1, and B2 symmetries, which correspond to C-H stretching and H-C-H bending modes. In line with the Herzberg-Teller principle, the influence of these molecular vibrations on the computed momentum profiles can be unraveled from considerations on the symmetry characteristics of orbitals and their <span class="hlt">energy</span> spacing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22224277','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22224277"><span><span class="hlt">Ground-state</span> and dynamical properties of two-dimensional dipolar Fermi liquids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Abedinpour, Saeed H.; Asgari, Reza; Tanatar, B.; Polini, Marco</p> <p>2014-01-15</p> <p>We study the <span class="hlt">ground-state</span> properties of a two-dimensional spin-polarized fluid of dipolar fermions within the Euler–Lagrange Fermi-hypernetted-chain approximation. Our method is based on the solution of a scattering Schrödinger equation for the “pair amplitude” √(g(r)), where g(r) is the pair distribution function. A key ingredient in our theory is the effective pair potential, which includes a bosonic term from Jastrow–Feenberg correlations and a fermionic contribution from kinetic <span class="hlt">energy</span> and exchange, which is tailored to reproduce the Hartree–Fock limit at weak coupling. Very good agreement with recent results based on quantum Monte Carlo simulations is achieved over a wide range of coupling constants up to the liquid-to-crystal quantum phase transition. Using the fluctuation–dissipation theorem and a static approximation for the effective inter-particle interactions, we calculate the dynamical density–density response function, and furthermore demonstrate that an undamped zero-sound mode exists for any value of the interaction strength, down to infinitesimally weak couplings. -- Highlights: •We have studied the <span class="hlt">ground</span> <span class="hlt">state</span> properties of a strongly correlated two-dimensional fluid of dipolar fermions. •We have calculated the effective inter-particle interaction and the dynamical density–density response function. •We have shown that an undamped zero sound mode exists at any value of the interaction strength.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22415934','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22415934"><span>Long-range interactions between polar bialkali <span class="hlt">ground-state</span> molecules in arbitrary vibrational levels</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vexiau, R.; Lepers, M. Aymar, M.; Bouloufa-Maafa, N.; Dulieu, O.</p> <p>2015-06-07</p> <p>We have calculated the isotropic C{sub 6} coefficients characterizing the long-range van der Waals interaction between two identical heteronuclear alkali-metal diatomic molecules in the same arbitrary vibrational level of their ground electronic state X{sup 1}Σ{sup +}. We consider the ten species made up of {sup 7}Li, {sup 23}Na, {sup 39}K, {sup 87}Rb, and {sup 133}Cs. Following our previous work [Lepers et al., Phys. Rev. A 88, 032709 (2013)], we use the sum-over-state formula inherent to the second-order perturbation theory, composed of the contributions from the transitions within the <span class="hlt">ground</span> <span class="hlt">state</span> levels, from the transition between <span class="hlt">ground-state</span> and excited state levels, and from a crossed term. These calculations involve a combination of experimental and quantum-chemical data for potential <span class="hlt">energy</span> curves and transition dipole moments. We also investigate the case where the two molecules are in different vibrational levels and we show that the Moelwyn-Hughes approximation is valid provided that it is applied for each of the three contributions to the sum-over-state formula. Our results are particularly relevant in the context of inelastic and reactive collisions between ultracold bialkali molecules in deeply bound or in Feshbach levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19916613','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19916613"><span>The thermodynamic and <span class="hlt">ground</span> <span class="hlt">state</span> properties of the TIP4P water octamer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Asare, E; Musah, A-R; Curotto, E; Freeman, David L; Doll, J D</p> <p>2009-11-14</p> <p>Several stochastic simulations of the TIP4P [W. L. Jorgensen, J. Chandrasekhar, J. D. Madura, R. W. Impey, and M. L. Klein, J. Chem. Phys. 79, 926 (1983)] water octamer are performed. Use is made of the stereographic projection path integral and the Green's function stereographic projection diffusion Monte Carlo techniques, recently developed in one of our groups. The importance sampling for the diffusion Monte Carlo algorithm is obtained by optimizing a simple wave function using variational Monte Carlo enhanced with parallel tempering to overcome quasiergodicity problems. The quantum heat capacity of the TIP4P octamer contains a pronounced melting peak at 160 K, about 50 K lower than the classical melting peak. The zero point <span class="hlt">energy</span> of the TIP4P water octamer is 0.0348+/-0.0002 hartree. By characterizing several large samples of configurations visited by both guided and unguided diffusion walks, we determine that both the TIP4P and the SPC [H. J. C. Berendsen, J. P. Postma, W. F. von Gunsteren, and J. Hermans, (Intermolecular Forces, Reidel, 1981). p. 331] octamer have a <span class="hlt">ground</span> <span class="hlt">state</span> wave functions predominantly contained within the D(2d) basin of attraction. This result contrasts with the structure of the global minimum for the TIP4P potential, which is an S(4) cube. Comparisons of the thermodynamic and <span class="hlt">ground-state</span> properties are made with the SPC octamer as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EL.....9847005B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EL.....9847005B"><span>Finite-size corrections for <span class="hlt">ground</span> <span class="hlt">states</span> of Edwards-Anderson spin glasses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boettcher, Stefan; Falkner, Stefan</p> <p>2012-05-01</p> <p>Extensive computations of <span class="hlt">ground-state</span> <span class="hlt">energies</span> of the Edwards-Anderson spin glass on bond-diluted, hypercubic lattices are conducted in dimensions d=3, ..., 7. Results are presented for bond densities exactly at the percolation threshold, p=pc, and deep within the glassy regime, p>pc, where finding <span class="hlt">ground</span> <span class="hlt">states</span> is one of the hardest combinatorial optimization problems. Finite-size corrections of the form 1/Nω are shown to be consistent throughout with the prediction ω=1-y/d, where y refers to the "stiffness" exponent that controls the formation of domain wall excitations at low temperatures. At p=pc, an extrapolation for d→∞ appears to match our mean-field results for these corrections. In the glassy phase, however, ω does not approach its anticipated mean-field value of 2/3, obtained from simulations of the Sherrington-Kirkpatrick spin glass on an N-clique graph. Instead, the value of ω reached at the upper critical dimension matches another type of mean-field spin glass models, namely those on sparse random networks of regular degree called Bethe lattices.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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