... Title : Interpretation of Quadrupole Coupling Constants in Imidazole Using Electric Field Gradients from Ab Initio Wave Function. ...
DTIC Science & Technology
There has been a significant progress in ab initio approaches to the structure of light nuclei. Starting from realistic two- and three-nucleon interactions the ab initio no-core shell model (NCSM) predicts low-lying levels in p-shell nuclei. It is a chall...
National Technical Information Service (NTIS)
... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... in Ammonia from Ab Initio Wave ...
... softening of Al-based fcc alloys using ab initio Korringa-Kohn-Rostoker augmented-spherical-wave electronic structure calculations is discussed. ...
NMR chemical shifts for an L-alanine molecular crystal are calculated using ab initio plane wave density functional theory. Dynamical effects including anharmonicity may be included by averaging chemical shifts over an ensemble of structural configurations generated using molecular dynamics (MD). The time scales required mean that ...
PubMed
NASA Astrophysics Data System (ADS)
Polynomial expressions for the elastic tensor coefficients, the bulk, the shear and Young�s moduli, the speed of sound for longitudinal and transverse waves, the equation of state and the x coordinate of the sulfur atom in pyrite are reported based on ab initio calculations in the range of 0-135 GPa. Comparison with published ...
A method is outlined for the calculation of photoionization cross sections representing the initial state by a minimal basis set STO NG wavefunction and the final state by the plane wave approximation. Numberical results for several small molecules compar...
... This study involves: Ab-initio crystal orbitals and polymer orbitals; Ab-initio coupled cluster program; Ab-initio quantum chemical calculations and ...
We present results for the static and dynamic structural properties of undercooled liquid Si, at several temperatures between 1550 K and 1100 K, obtained through orbital-free ab-initio molecular dynamics simulations. The local bond angle distributions show a modest increase in the tetrahedral order upon decreasing the temperature. We also analyze the variation of several ...
The authors have calculated the band structures of organic conductors TTF-TCNQ and {beta}-(BEDT-TTF){sub 2}I{sub 3} using the ab initio plane-wave pseudopotential method within the local-density approximation (LDA). The Fermi-surface shape and the origin of bands near the Fermi level are investigated for each compound.
Energy Citations Database
We have investigated the electronic structure of TTF-TCNQ under uniaxial compression with ab initio plane-wave pseudopotential calculations within the local-density approximation and generalized gradient approximation. Depending on the compression direction, the constituent molecules are deformed in different ways. Along with these ...
We present a formulation of ab initio electronic structure calculations in a finite magnetic field, which retains the simplicity and efficiency of techniques widely used in first principles molecular dynamics simulations, based on plane-wave basis sets and Fourier transforms. In addition we discuss results obtained with this method for ...
DOE Information Bridge
... Title : Chalcopyrite Magnetic Semiconductors: An Ab-Initio Study of Their Structural, Electronic and Magnetic Properties. ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... COMPENDIUM OF AB INITIO CALCULATIONS ...
... Accession Number : ADA219907. Title : An Ab Initio Study of the Geometry and Rotational Barrier of 4- Phenylimidazole. ...
... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... Title : Ab Initio Calculations of the ...
... Title : Ab Initio Calculation of Vibrational Absorption and Circular Dichroism Spectra Using Density Functional Force Fields. ...
... Title : AB Initio Quantum Chemical Investigations of Solubilities in Supercritical Solutions. Descriptive Note : Conference Paper,. ...
The framework of ab initio density-functional theory (DFT) has been introduced as a way to provide a seamless connection between the Kohn-Sham (KS) formulation of DFT and wave-function based ab initio approaches [R. J. Bartlett, I. Grabowski, S. Hirata, and S. Ivanov, J. Chem. Phys. 122, 034104 ...
... Title : AB Initio Study of the Electronic Magnetic Circular Dichroism ... functions are determined using as initio quantum chemical techniques including ...
Almost all the ab inito studies performed so far for various (possible) Earth's inner core materials were conducted by comparing together the computed longitudinal (Vp) and shear (Vs) wave velocities to the first- order velocity term of seismological models. We here demonstrate that further constraints on the Earth's inner core composition can be provided ...
... for the wave function explansion inl the interst it iadl rgion, whereas a 49 RY cut ... that found Mnr,,Cd_(i.GeP 2 to be a room-temperature fer- romagnet ...
The nature of the bonding between halogen atoms (F, CI and Br) and the Ag (111) surface has been investigated by analyzing ab initio Hartree- Fock wave functions for cluster models of the Ag surface and a halogen atom. Using a variety of criteria, we conc...
Solid State Nuclear Magnetic Resonance (NMR) is a powerful tool in crystallography when combined with theoretical predictions. So far, empirical calculations of spectra have been employed for an unambiguous identification. However, many complex systems are outside the scope of these methods. Our implementation of ultrasoft and projector augmented wave pseudopotentials within ...
Due to recent advances in methods and computers, the accuracy of ab calculations has reached a point
NASA Technical Reports Server (NTRS)
For the equilibrium immiscible Fe-Cu system, ab initio calculations using the projector augmented wave method identify the relatively stable structures of the metastable Fe25Cu75 and Fe50Cu50 alloys to be both of fcc and determine their corresponding lattice constants and cohesive energies. Some of the ab ...
-wave /pseudopotential codes [2,5�7]. Parallelization of the CPMD code was done on different levels. The central-initio Molecular Dynamics: Reaching Teraflop Performance with the CPMD Code J�urg Hutter Physical Chemistry-level Parallelism for ab-initio Molecular Dynamics: Reaching Teraflop Performance with the CPMD Code J�urg ...
E-print Network
In this paper it is shown that the complex Shavitt functions Fn(z) can be interpolated in the same way as the real Shavitt functions Fn(x) in electronic structure theory. This greatly accelerates the evaluation of exchange integrals in a mixed Gaussian and plane-wave basis. Together with other approximations reported previously this extends applications of ...
The results of ab initio calculations of the vibronically averaged components of the anisotropic magnetic hyperfine tensor in the low-lying vibronic species of the X2? electronic state of the HCCS radical are reported. The electronically averaged hyperfine coupling constants for hydrogen, deuterium, 13C and 33S are obtained as functions of two bending ...
The rotational spectrum of chlorofluoroiodomethane (CHClFI) has been investigated. Because its rotational spectrum is extremely crowded, extensive ab initio calculations were first performed in order to predict the molecular parameters. The low J transitions were measured using a pulsed-molecular-beam Fourier transform spectrometer, and the ...
We study the effect of the splitting of neutron and proton effective masses with isospin asymmetry on the properties of the Skyrme energy density functional. We discuss the ability of the latter to predict observables of infinite matter and finite nuclei, paying particular attention to controlling the agreement with ab initio predictions of the ...
Gaussian 76 is a general-purpose computer program for ab initio Hartree-Fock molecular orbital calculations. It can handle basis sets involving s, p and d-type gaussian functions. Certain standard sets (STO-3G, 4-31G, 6-31G*, etc.) are stored internally for easy use. Closed shell (RHF) or unrestricted open shell (UHF) wave functions ...
To assist the proposed search for the electric dipole moment of the electron with the thorium oxide, converged ab initio coupled cluster calculations are performed on the interaction energy, dipole moment, anisotropic static dipole polarizability, and quadrupole moment of the ThO(X 1?+) molecule as functions of internuclear distance. The rovibrational ...
To assist the proposed search for the electric dipole moment of the electron with the thorium oxide, converged ab initio coupled cluster calculations are performed on the interaction energy, dipole moment, anisotropic static dipole polarizability, and quadrupole moment of the ThO(X (1)Sigma(+)) molecule as functions of internuclear distance. The ...
The total energy of a grain boundary in a transition metal is calculated in an {ital ab} {ital initio} manner. Such calculations are now feasible using a plane-wave basis set provided that an optimally convergent pseudopotential is used. The investigation focuses on resolving two competing atomic models for the {Sigma}=5 (001) twist ...
The photoelectron spectra of the weakly bound KrO- anion are simulated using a theory which combines the atoms-in-molecule model for molecular electronic wave functions and the Rau-Fano model for photodetachment intensities [J. Chem. Phys. 112, 5852 (2000)]. The nonrelativistic potential energy curves of the anion are obtained from ab ...
The Cytochrome P450 superfamily of enzymes are of great interest in pharmacology as they participate in an enormous range of physiological processes including drug deactivation and xenobiotic detoxification. We apply ab initio electronic structure calculations to model the interactions of the haem molecule at the P450 active site with substrate and ...
... AB-INITIO SIMULATION OF a/2110> ... 4. TITLE AND SUBTITLE AB-INITIO SIMULATION OF a/2110> SCREW DISLOCATIONS γ-TiAl 5c. ...
... ADP012740 TITLE: Ab Initio Study on Spin Polarization of III-V Compound Tips ... Ab initio study on spin polarization of III-V compound tips ...
Ab initio electronic structure methods can supplement CALPHAD in two major ways for subsequent applications to stability in complex alloys. The first one is rather immediate and concerns the direct input of ab initio energetics in CALPHAD databases. The o...
...with this part. The certificate shall be void ab initio for those vehicles causing the...issued, and the certificate may be deemed void ab initio. (C) The manufacturer...with this part. The certificate shall be void ab initio for those vehicles causing...
Code of Federal Regulations, 2010
We present full-dimensional potential energy surfaces (PESs) for hydrated chloride based on the sum of ab initio (H(2)O)Cl(-), (H(2)O)(2), and (H(2)O)(3) potentials. The PESs are shown to predict minima and corresponding harmonic frequencies accurately on the basis of comparisons with previous and new ab initio ...
Quantum chemical calculations of energies, geometrical structure and vibrational wave numbers of 3,4-dimethoxybenzonitrile (DMBN) were carried out by the ab initio Hartree-Fock (HF) and density functional theory (DFT) with complete relaxation in the potential energy surface using 6-311++G(d,p) basis set. The computed values of ...
The ab initio calculation with the density functional theory and plane-wave bases is carried out for stepped Si(111)?2�1 surfaces that were predicted in a cleavage simulation by the large-scale (order-N) electronic structure theory (T. Hoshi, Y. Iguchi and T. Fujiwara, Phys. Rev. B 72 (2005) 075323). The present ...
There has been a significant progress in ab initio approaches to the structure of light nuclei. Starting from realistic two- and three-nucleon interactions the ab initio no-core shell model (NCSM) predicts low-lying levels in p-shell nuclei. It is a challenging task to extend ab ...
... ADP023770. Title : ab-Initio Molecular Dynamics Simulations of Molten Ni-Based Superalloys. Descriptive Note : Conference paper. ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... of Molecular Modelling and Ab initio Molecular ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : New AB Initio Based Density ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Development of Ab-initio Multibody ...
... Ab initio Energies Calculated Using 3 ... of the Transition States (TS ... Descriptors : *TRANSITIONS, *MOLECULES, COMPUTATIONS, COMPARISON ...
... Abstract : Results are presented from ab initio quantum chemical calculations on the ground state potential energy surface for the open shell ...
... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... Title : An Ab Initio Study of Solid ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : An AB Initio Study of Dimethyl ...
... Accession Number : ADA523968. Title : Ab-initio Simulations of Molten Ni Alloys. Descriptive Note : Journal article (preprint). ...
... Title : Ab-Initio Molecular Dynamics Simulations of Molten Ni-Based Superalloys. Descriptive Note : Conference paper (preprint). ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab-Initio Molecular Dynamics Simulations ...
... We carried out ab-initio quantum chemical calculations on these energetic cyclic ethers and generated the electrostatic molecular potential contour ...
Ab initio quantum chemical techniques have been used to investigate weakly bund complexes of H20 and SO2. An energy gradient program was used to ...
NASA Website
... Accession Number : ADA351780. Title : Ab Initio and DFT Potential Energy Surfaces for Cyanuric Chloride Reactions. Descriptive Note : Final rept. ...
... Ab initio study on atomic structures and physical properties of CdSe quantum nanodots ... Figure 2. Diagram of covered nanodots. ...
... Title : Ab Initio Study on Atomic Structures and Physical Properties of CdSe Quantum Nanodots. Descriptive Note : Final rept. ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : Ab Initio Study of the Structure ...
... Rydberg I 'Flu state. Demoulin and Jungen (1974) used an ab initio quantum chemical approach, but only at the SCF level ...
... moment has been cancelled a priori for the electronic transition as a function of R(CC), using ab initio quantum chemical techniques including state ...
... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... Title : Ab Initio Study of Ultracold ...
1 AB INITIO STUDIES ON HEXAVALENT PHOSPHORUS COMPOUNDS Ashley L. Wilson* Aberdeen High School Aberdeen, Maryland 21001 ...
... Accession Number : ADA436055. Title : Ab Initio Studies on Hexavalent Phosphorus Compounds. Descriptive Note : Conference paper. ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : Ab Initio Relativistic Study of ...
... Accession Number : ADA440631. Title : Ab Initio Quantum Chemical Study of Electron Transfer in Carboranes. Descriptive Note : Journal article. ...
... Accession Number : ADA270577. Title : Ab Initio Potential Energy Surface for the H + OCS Reaction. Descriptive Note : Final rept. ...
... [2"- ARMY RESEARCH LABORATORY [C Ab Initio Potential Energy Surface for H + OCS Reactions: Extended Basis Sets ...
... Results of this study substantiate findings from an earlier quantum chemical study using a lower ... for (I) and (II) based on the earlier ab initio study. ...
... Ab initio direct trajectory simulation on hydrogen atom transfer in 7-azaindole in the electronic excited state with assist of water molecules ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab Initio Direct Trajectory Simulation on ...
... Title : Ab Initio Calculation of Vibrational Circular Dichroism Spectra Using Accurate Post-Self-Consistent-Field Force Fields: trans-2,3 ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab Initio Calculation of Intermolecular ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : AB Initio Propagator Theory of ...
A hydrodynamic equation describing the linear evolution of a nondissipative Langmuir wave in inhomogeneous nonstationary anisotropic plasma without magnetic field is derived in the geometrical optics approximation. The continuity equation for the wave action density, anticipated from general principles, is then confirmed ab ...
molecules Test Case2: 64 atom Si The CPMD code is a plane wave/pseudopotential implementation of Density IBM eServer OpenPower CPMD Version 3.9.2 The CPMD code is a plane wave/pseudopotential implementation Functional Theory, particularly designed for ab-initio molecular dynamics. CPMD Version 3.9.2 Life Sciences
Induced magnetization densities determined from an ab initio augmented-plane-wave wave-function study of Pd metal including local density-of-states effects on the Fermi surface were found to yield a neutron magnetic from factor in excellent agreement with...
Interrelations between the local and the global aspects of the stability, continuity, and symmetry properties of variational wave functions are discussed. The spherical limit of one-electron diatomic molecules and the Hartree-Fock approximation of the ground state of the two-electron atom are shown to exhibit the various concepts involved in an ab ...
Single-active-electron potentials are computed for selected molecules, and molecular wave functions with the correct asymptotic behavior are produced. Asymptotic expansion coefficients are extracted from the wave functions and used to compute alignment-dependent ionization yields from molecular tunneling theory. The predictions of molecular tunneling ...
First-principles density-functional calculations utilizing ab initio pseudopotentials and plane-wave expansions are used to determine lattice parameters, bulk moduli, and band structures for AlN, GaN and InN. It is found that large numbers of plane waves ...
Formulae are derived for the configuration interaction (CI) energy gradient where the CI is based upon a two-configuration self-consistent-field (TCSCF) reference wave function. A derivation of the analytic CI energy second derivative is presented in Chap...
The pseudofunction energy-band method is a full potential, ab initio technique with no adjustable parameters. The basis function is related to the pseudofunction used to create ab initio pseudopotentials. Orthogonalization of the pseudofunction to the core states is accomplished as in the augmented ...
In the beginning of the modern quantum theory of atomic and molecular spectra, the semi-empirical methods were exceedingly successful in explaining the structure of the spectra and their general properties, and it was hence somewhat of a surprise that, when the fundamental semi-empirical parameters were later calculated by ab initio methods, one would ...
We report on the determination of a high quality ab initiu potential energy surface (PES) and dipole
The interaction-induced contribution to the NMR shielding constants in homonuclear A2 and heteronuclear AB (A,B=He,Ne,Ar) dimers is obtained ab initio by employing a coupled cluster singles and doubles with perturbative treatment of triples wave function model and extended correlation-consistent basis sets. The ...
We report a full dimensional, ab initio-based global potential energy surface (PES) and dipole moment surface for Cl-H2O. Both surfaces are symmetric with respect to interchange of the H atoms. The PES is a fit to thousands of electronic energies calculated using the coupled-cluster method [CCSD(T)] with a moderately large basis (aug-cc-pVTZ). Vibrational ...
We report plane-wave pseudo-potential ab initio calculations using density functional theory in order to investigate the structural parameters, elastic constants, bonding properties and polycrystalline parameters of copper nitrides in zincblende, rocksalt and fluorite structures. Total and partial densities of states indicate a ...
The structural, electronic, and phonon properties of the cubic and tetragonal phase of SrTiO3 and BaTiO3 are studied from ab initio. The calculations are performed in the projector augmented wave density-functional theory framework using the local density approximation, gradient corrected functionals, and hybrid functional as ...
In order to apply ab initio wave-function-based correlation methods to metals, it is desirable to split the calculation into a mean-field part and a correlation part. Whereas the mean-field part (here Hartree-Fock) is performed in the extended periodic system, it is necessary to use for the correlation part local ...
The electronic structure of the charge density wave (CDW) bronze (PO2)(4)(WO3)(2m), m = 4, is determined using ab initio density functional theory. The calculation shows that the Fermi surface (FS) consists in the superposition of three one-dimensional FS's associated with three types of chains. The q dependence of the electronic ...
We study how the Mott metal-insulator transition (MIT) is affected when we have to deal with electrons with different angular momentum quantum numbers. For that purpose we apply ab initio quantum-chemical methods to lithium rings in order to investigate the analog of a MIT. By changing the interatomic distance we analyze the character of the many-body ...
