The Fourier inversion of phased coherent diffraction patterns offers images without the resolution and depth-of-focus limitations of lens-based tomographic systems. We report on our recent experimental images inverted using recent developments in phase retrieval algorithms, and summarize efforts that led to these accomplishments. These include ab-initio ...

... This is being done by carrying out theoretical high quality three-dimensional ab-initio quantum chemical calculations on the oximes and from these ...

We report the development of a novel form of diffraction-based 3D microscopy to overcome resolution barriers inherent in high-resolution electron microscopy and tomography. By combining coherent electron diffraction with the oversampling phasing method, we show that the 3D structure of a nanocrystal can be determined ab initio at a ...

The third-order susceptibility of H2 has been calculated under coherent anti-Stokes Raman-scattering

Three-dimensional diffraction microscopy offers the potential for high-resolution aberration-free diffraction-limited 3D images without the resolution and depth-of-field limitations of lens-based tomographic systems. Critical issues in obtaining a high-quality image include: (1) Data collection--signal to noise, system stability, dynamic range, automation; (2) Alignment of ...

We report a highly correlated multireference configuration interaction calculation of the near-equilibrium potential energy surface of ozone using a large correlation consistent basis set. Three-dimensional analytical expressions are obtained for the potential energy and dipole moment functions using least-squares fits to ab initio ...

In this work, we introduce a new analytical form based on the q-exponential function to build three-dimensional reactive surfaces. The quality of this new function is tested by fitting the ab initio potential energy surface (PES) to the ground state Na+HF reaction. The thermal rate constant and reactive probabilities were determined ...

We present a new linear scaling ab initio total energy electronic structure calculation method based on the divide-and-conquer strategy. This method is simple to implement, easily to parallelize, and produces very accurate results when compared with the direct ab initio method. The method has been tested using up ...

Coherent X-ray diffraction microscopy is a method of imaging non-periodic isolated objects at resolutions only limited, in principle, by the largest scattering angles recorded. We demonstrate X-ray diffraction imaging with high resolution in all three dimensions, as determined by a quantitative analysis of the reconstructed volume images. These images are retrieved from the 3D ...

The interaction potential energy surface (PES) of H4 is of great importance for quantum chemistry as a test case for molecule-molecule interactions. It is also required for a detailed understanding of certain astrophysical processes, namely collisional excitation and dissociation of H2 in molecular clouds, at densities too low to be accessible experimentally. The 6101 ab ...

Contents: Ab Initio Powder Diffraction; Alloys; Amorphous Materials; Aqueous Solutions; Atomic Spectroscopy; Biological Spectroscopy; Biominerals; Catalysts; Ceramics and Glass; Chemistry; Coherence/Correlation in Innershell Processes; Combined Techniques...

We report herein a series of ab initio simulations of water under both static and shocked conditions. We have calculated the coherent x-ray scattering intensity of several phases of water under high pressure, using ab initio Density Functional Theory (DFT). We provide new atomic scattering form ...

A multiscale theoretical approach (ab initio and Grand Canonical Monte Carlo calculations) was used to investigate hydrogen storage in a novel three-dimensional carbon nanostructure. Our results show that a large-pore PNN can overpass the gravimetric capacity of 20% at 77 K while a Li-doped PNN can reach the value of 8% at room ...

We present a new linearly scaling three-dimensional fragment (LS3DF) method for large scale ab initio electronic structure calculations. LS3DF is based on a divide-and-conquer approach, which incorporates a novel patching scheme that effectively cancels o...

The Linearly Scaling three-dimensional fragment (LS3DF) method is an O(N) ab initio electronic structure method for large-scale nano material simulations. It is a divide-and-conquer approach with a novel patching scheme that effectively cancels out the ar...

We present a new linearly scaling three-dimensional fragment (LS3DF) method for large scale ab initio electronic structure calculations. LS3DF is based on a divide-and-conquer approach, which incorporates a novel patching scheme that effectively cancels o...

Using a quasi-ab initio molecular-dynamics method we have studied two-dimensional (2D) versus three-dimensional (3D) structures in Co clusters deposited on Cu(001) finding that the magnetism plays a relevant role. For the magnetic Co25 supported cluster, the influence of such a 2D to 3D structural change on the magnetic properties ...

Model-based, three-dimensional (3D) image reconstruction procedures require a starting model to initiate data analysis. We have designed an ab initio method, which we call the random model (RM) method, that automatically generates models to initiate structural analysis of icosahedral viruses imaged by cryo-electron microscopy. The ...

The self-consistent cluster-embedding (SCCE) calculation method reduces the computational effort from M3 to about M1 (M is the number of atoms in the system) with unchanged calculation precision. So the ab initio, all-electron calculation of the electronic structure and biological function of protein molecule becomes a reality, which will promote new ...

The self-consistent cluster-embedding (SCCE) calculation method reduces the computational effort from M3 to about M1 (M is the number of atoms in the system) with precise calculations. Thus the ab initio, all-electron calculation of the electronic structure and biological function of protein molecule has become a reality, which will promote new proteomics ...

A new high quality three-dimensional potential energy surface for the Ne-CO van der Waals complex is developed using the CCSD(T) method and avqz/avqz+33221 basis set. The ab initio calculation is performed in a total of 1365 configurations with supermolecule method. There is a single global minimum located in a nearly T-shaped ...

We present a novel linear scaling ab initio total energyelectronic structure calculation method, which is simple to implement,easily to parallelize, and produces essentially thesame results as thedirect ab initio method, while it could be thousands of times faster.Using this method, we have studied the dipole ...

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 frequencies are scaled using ...

We give an improved estimate of the detectability of gravitational waves from magnetically confined mountains on accreting neutron stars. The improved estimate includes the following effects for the first time: three-dimensional hydromagnetic (`fast') relaxation, three-dimensional resistive (`slow') relaxation, realistic accreted masses Ma <~ 2 � ...

Three-dimensional quantum mechanical calculations on the vibrational predissociation dynamics of HeI2 B state complex are performed using a potential energy surface accurately fitted to unrestricted open-shell coupled cluster ab initio data, further enabling extrapolation for large I2 bond lengths. A Lanczos iterative method with an ...

Three-dimensional low-resolution models of the biochemically and biotechno- logically significant enzyme cellobiose dehydrogenase (CDH) were predicted by advanced modeling approaches based on experimental one-dimensional low-resolution small-angle x-ray scattering (SAXS) data. In particular, the ab initio modeling program DAMMIN by ...

Large three-dimensional (3D) particle-in-cell (PIC) simulations have been performed using the VPIC code on some of the world's largest supercomputers, including the Roadrunner supercomputer, the first machine capable of a petaflop/s. These simulations have revealed the complex physical mechanisms underlying laser-plasma interactions and show an emerging universal picture of ...

... This study involves: Ab-initio crystal orbitals and polymer orbitals; Ab-initio coupled cluster program; Ab-initio quantum chemical calculations and ...

The dynamics of an ionization and a recombination in an ultrastrong laser field is studied by ab initio numerical simulations performed for a realistic atomic system in the regime of attosecond laser pulse duration. In particular the stabilization phenomenon is studied, the presence of which is confirmed in 3D. We first describe the method of integrating ...

To explain the recent successful three-dimensional atom probe (3DAP) analyses of insulating oxides by laser assisted field evaporation, we investigated the mechanism of the laser-induced field evaporation of oxides by ab initio calculations. The calculated potential energy surfaces (PESs) for the ground and excited states indicated ...

... 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,. ...

Vibrational eigenfunctions are calculated on-the-fly using semiclassical methods in conjunction with ab initio density functional theory classical trajectories. Various semiclassical approximations based on the time-dependent representation of the eigenfunctions are tested on an analytical potential describing the chemisorption of CO on Cu(100). Then, ...

Vibrational eigenfunctions are calculated on-the-fly using semiclassical methods in conjunction with ab initio density functional theory classical trajectories. Various semiclassical approximations based on the time-dependent representation of the eigenfunctions are tested on an analytical potential describing the chemisorption of CO on Cu(100). Then, ...

For a class of transition metal materials residual resistivity is observed to decrease when the materials are deformed and short-range order is removed. We investigate this counter-intuitive behavior with an ab initio theoretical study of the residual resistivity of several late transition metal-rich disordered alloys. The calculations are performed using ...

A direct calculation of the coherent x-ray scattering spectrum of liquid water under ambient conditions is presented using ab initio density functional theory. The experimental data are compared with the calculated x-ray scattering spectra retrieved from the trajectories of two Car-Parrinello molecular dynamics runs of about 10 ps with ...

Ab initio total energy calculations based on the exact muffin-tin orbitals method, combined with the coherent potential approximation, have been used to study the thermodynamical and elastic properties of substitutional refractory Ru1-xNixAl alloys. We have found that the elastic constants C' and C11 exhibit pronounced peculiarities ...

The FT-IR and FT-Raman spectra of 3-Bromo phenol (3-BP) molecule have been recorded using Bruker IFS 66V spectrometer in the range of 4000-100 cm(-1). The molecular geometry and vibrational frequencies in the ground state are calculated by using the ab initio Hartree-fock (HF) and DFT (B3LYP) methods with 6-31G (d, p) and 6-311G (d, p) basis sets. The ...

The physical reliability and foundations of the Hund-H�ckel MO-LCAO model, in which a molecular orbital (MO) is represented as a linear combination of atomic orbitals (LCAO), are examined in light of ab initio self-consistent field (SCF) computations with bases of various sizes. It is shown that appropriate linear transformations of the basis make ...

Based on ab initio simulations of the interaction of the hydrogen atom with a multifrequency ultrashort laser pulse in the strong-field regime, coherent population trapping is found. It leads to the inhibition of the ionization process and, hence, electromagnetically induced transparency, provided that certain two-photon resonance ...

The diffusion coefficient of liquid aluminium has been obtained through coherent quasielastic neutron scattering. The resulting values agree well with calculations derived from the viscosity applying the Stokes-Einstein relation and with ab initio calculations. The temperature dependence of the diffusion constant displays an ...

Coherent anti-Stokes Raman spectroscopy (CARS) is combined with high-resolution interferometry to measure the absolute Raman shift of the Q(2) vibrational line in D(2). The preliminary value found is 2987.237(1) +/- 0.001 cm(-1). Such precision is essential for the testing of ab initio energy-level calculations for the hydrogen ...

Coherent anti-Stokes Raman spectroscopy (CARS) is combined with high-resolution interferometry to measure the absorlute Raman shift of the Q (2) vibrational line in D/sub 2/. The preliminary value found is 2987.237/sub 1/ +- 0.001 cm/sup -1/. Such precision is essential for the testing of ab initio energy-level calculations for the ...

ccsd-00018218,version1-30Jan2006 Real time Quantum state holography using coherent transients (1999). [34] V. Wong and I. A. Walmsley, "Linear filter analysis of methods for ultrashort pulse shape

The third-order susceptibility of H/sub 2/ has been calculated under coherent anti-Stokes Raman-scattering conditions, with use of wave functions specifically designed for accurate calculations of sum-rule properties. The theoretical values are in good agreement with experiment.

We study tunnel ionized electron wave packet dynamics during the initial transition from a gas to a plasma by detecting the terahertz radiation emitted in the process. Experimental and theoretical results show that much of the observed radiation is due to coherent buildup of bremsstrahlung released during the first electron-atom collision. Coherent control ...

The Linearly Scaling three-dimensional fragment (LS3DF) method is an O(N) ab initio electronic structure method for large-scale nano material simulations. It is a divide-and-conquer approach with a novel patching scheme that effectively cancels out the artificial boundary effects, which exist in all divide-and-conquer schemes. This ...

The linearly scaling three-dimensional fragment (LS3DF) method is an O(N) ab initio electronic structure method for large-scale nano material simulations. It is a divide-and-conquer approach with a novel patching scheme that effectively cancels out the artificial boundary effects, which exist in all divide-and-conquer schemes. This ...

The Linearly Scaling three-dimensional fragment (LS3DF) method is an O(N) ab initio electronic structure method for large-scale nano material simulations. It is a divide-and-conquer approach with a novel patching scheme that effectively cancels out the artificial boundary effects, which exist in all divide-and-conquer schemes. This ...

We report the results of numerical simulations of random, three-dimensional, periodic, tetrafunctional networks in response to a volume-preserving tensile strain. For the intranode force, we use a polynomial fit to a purely enthalpic ab initio force extension curve for extended polyisoprene. The simulation includes a relaxation ...

We report the results of numerical simulations of random, three-dimensional, periodic, tetrafunctional networks in response to a volume-preserving tensile strain. For the intranode force, we use a polynomial fit to a purely enthalpic ab initio force extension curve for extended polyisoprene. The simulation includes a relaxation ...

We report the results of numerical simulations of random, three-dimensional, periodic, tetrafunctional networks in response to a volume-preserving tensile strain. For the intranode force, we use a polynomial fit to a purely enthalpic ab initio force extension curve for extended polyisoprene. The simulation includes a relaxation ...

The wavelength-dependent isotopic fractionation of N(2)O is calculated, extending our previous work, Parts 1 and 2, in several aspects: (1) the fully three-dimensional ab initio electronic potential and transition dipole moment surfaces of S. Nanbu and M. S. Johnson (J. Chem. Phys. A 2004, 108, 8905) are used to calculate the ...

A new high quality three-dimensional potential energy surface for the Ne-CO van der Waals complex is developed using the CCSD(T) method and avqz?avqz+33221 basis set. The ab initio calculation is performed in a total of 1365 configurations with supermolecule method. There is a single global minimum located in a nearly T-shaped ...

... in electron energy and beam divergence and on material properties such as dielectric permittivities and the resultant coherence length upon the ...

Noninvasive ophthalmic angiography is demonstrated for the in vivo human. Three-dimensional structural and flow imaging have been performed with a high-speed spectral-domain optical coherence tomography. The two methods are presented; (1) Doppler optical coherence angiography: three-dimensional vasculature of ...

We calculate the spectral line shape of an isolated line from first principles, assuming that the translational motion is not statistically correlated with the evolution of the optical coherence, i.e., with the broadening. We use the known, realistic potentials for the influence of collisions on the translational motion and on the internal motion. We show that the calculated ...

A mechanism by which NH stretching quanta are coherently transported along a chain of hydrogen bonded peptide groups is demonstrated by classical simulation of a section of the alpha-helical peptide poly(L-alanine). Vibrational motion takes place on a complex energy surface constructed from earlier ab initio and empirical surfaces. A ...

We report on ab initio-based simulations of friction-force microscopy on the KBr(001) surface at zero and nonzero temperature. To simulate sliding friction, we employ an extended three-dimensional (3D) Prandtl-Tomlinson model. The microscopic part of the tip is modeled by K+- or Br--terminated tips. We use a tip-surface interaction ...

Zn (CN)2 and Ni(CN)2 are known for exhibiting anomalous thermal expansion over a wide temperature range. The volume thermal expansion coefficient for the cubic, three-dimensionally connected material, Zn(CN)2, is negative (?V=-51�10-6K-1) while for Ni(CN)2, a tetragonal material, the thermal expansion coefficient is negative in the two-dimensionally connected sheets ...

The entrance channel of the Si+O2-->SiO+O reaction has been investigated for collinear and perpendicular approach of the silicon atom to the O2 molecule by ab initio electronic structure calculations using the multireference configuration interaction (MRCI) method and Davidson correction (MRCI+Q). Results show that the reaction can proceed through the ...

Light beams carrying orbital angular momentum (OAM), such as Laguerre-Gaussian (LG) beams, give rise to the violation of the standard dipolar selection rules during interaction with matter, yielding, in general, an exchange of angular momentum larger than planck per absorbed photon. By means of ab initio three-dimensional (3D) ...

We study the electrostatic potential of a molecular wire bridging two metallic electrodes in the limit of weak contacts. With the use of a tight-binding model including a fully three-dimensional treatment of the electrostatics of the molecular junction, the potential is shown to be poorly screened, dropping mostly along the entire molecule. In addition, we observe pronounced ...

We present the first observations of zero-n[over ] band gaps in photonic crystal superlattices consisting of alternating stacks of negative-index photonic crystals and positive-index dielectric materials in the near-infrared range. Guided by ab initio three-dimensional numerical simulations, the fabricated nanostructured superlattices ...

We use intense few-cycle laser pulses to ionize molecules to the point of Coulomb explosion. We use Coulomb's law or ab initio potentials to reconstruct the molecular structure of D{sub 2}O and SO{sub 2} from the correlated momenta of exploded fragments. For D{sub 2}O, a light and fast system, we observed about 0.3 A and 15 deg. deviation from the ...

A self-consistent linear scaling three-dimensional fragment (LS3DF) method is used to study the dipole moments and internal electric fields of large ZnO nanorods. Our ab initio calculations reveal that the ZnO nanorod with unpassivated (1010) side surface has a side surface contribution per Zn-O dimer 10 times larger than the bulk ...

We report correlated two-electron ab initio calculations for the hydrogen molecule H{sub 2} in interaction with intense ultrashort laser pulses, via a solution of the full three-dimensional time-dependent Schroedinger equation. Our results for ionization and excitation probabilities (at 800 and 400 nm) as a function of internuclear ...

We show that the dominant eigenvectors of real protein structural contact matrices are highly correlated with their amino acid sequences. These results suggests that an ab initio sequence-independent profile exists for every protein structure and that this profile is highly effective in differentiating the ordering of amino acids in natural protein ...

In contrast with the single atom, atomic van der Waals clusters can form stable anions where the excess electron is bound due to long-range correlations with the electrons of the cluster. We report on extensive all-electron many-body ab initio studies on Xe clusters. Three-dimensional, planar, and linear structures of the clusters are ...

Optimal control of rovibrational excitations of the CO molecule using picosecond infrared laser pulses is described in the framework of the electric-nuclear Born-Oppenheimer approximation [G. G. Balint-Kurti et al., J. Chem. Phys. 122, 084110 (2005)]. The potential energy surface of the CO molecule in the presence of an electric field is calculated using coupled cluster theory with a large orbital ...

... 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...

We investigated the spectroscopy of the first excited singlet electronic state S1 of 2-phenylindene using both fluorescence excitation spectroscopy and resonantly enhanced multiphoton ionization spectroscopy. Moreover, we investigated the dynamics of the S1 state by determining state-selective fluorescence lifetimes up to an excess energy of approximately 3400 cm(-1). Ab ...

The electronic structure of disordered Sr1-xKxFe2As2 is studied by ab initio density functional theory. As no superstructure and/or atomic short range ordering is reported for Sr1-xKxFe2As2, the coherent potential approximation can be used to describe the effects of chemical disorder. We find clear deviations from the rigid band model ...

... 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 ...

... 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 ...

... 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 ...

... Title : AB Initio Study of the Electronic Magnetic Circular Dichroism ... functions are determined using as initio quantum chemical techniques including ...

... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : AB Initio Propagator Theory of ...

We perform a systematic ab initio study of the interface energetics of thin coherent rocksalt (nacl) structured MN and tetragonal CrMN films in bcc Fe (M = V, Nb, Ta), motivated by the vital role of MN and CrMN precipitates for the long-term creep resistance in 9%-12%Cr steels. The similarities and differences in the work of ...

For many years, theoretical studies using model and ab initio potentials have predicated the existence of a liquid/liquid phase transition in silicon, based on a continuous change of the liquid A5 structure to A4. In contrast, we report here a quantitative analysis of data from high-energy X-ray diffraction measurements of containerlessly-processed ...

The origin of dramatic variation in optical polarizabilities of push-pull conjugated chains with respect to the conjugation length is discussed. Ab initio calculations of intramolecular charge transfer (ICT)-driven dipole moment (?CT), polarizability (?CT), and first hyperpolarizability (?CT) show that the values of ?CT/?CT and ?CT/?CT change linearly and ...

Quantum interference in coherent transport through single molecular rings may provide a mechanism to control the current in molecular electronics. We investigate its applicability, using a single-particle Green function method combined with ab initio electronic structure calculations. We find that the quantum interference effect (QIE) ...

Quantum interference in coherent transport through single molecular rings may provide a mechanism to control current in molecular electronics. We investigate its applicability by using a single-particle Green function method combined with ab initio electronic structure calculations. We find that the quantum interference effect (QIE) ...

The formalism and the experimental conditions under which coherent inelastic x-ray scattering from phonons can be utilized to determine the vibrational density of states are presented. The validity of the approach is checked by comparison of results for diamond and MgO with ab initio lattice dynamics calculations and thermodynamic ...

We present a microscopic theory of the anomalous Hall effect (AHE) in metallic multiband ferromagnets, which accounts for all scattering-independent contributions, i.e., both the intrinsic and the so-called side jump. For a model of Gaussian disorder, the AHE is expressed solely in terms of the material�s electronic band structure. Our theory handles systematically the interband-scattering ...

Sterical (van der Waals-induced) rotational barriers of methyl groups are investigated theoretically, using ab initio and empirical force field calculations, for various three-dimensional microenvironmental conditions around the methyl group rotator of a model neopentane molecule. The destabilization (reducing methyl rotational ...

Three-dimensional electronic structure of highly metallic sodium tungsten bronze, Na0.8WO3 , is investigated by high-resolution angle-resolved photoemission spectroscopy. The experimentally determined valence-band structure along the momentum directions both parallel and perpendicular to the surface has been compared with the results of ab ...

Eight fascinating sp2- and sp3-hybridized carbon allotropes have been uncovered using a new ab initio evolutionary methodology for crystal structure prediction. These crystalline allotropes can be viewed respectively as three dimensional (3D) polymers of (4,0), (5,0), (7,0), (8,0), (9,0), (3,3), (4,4), and (6,6) ...

The aim of this collaborative research work was to apply predictive, physically based multiscale modeling to improve understanding of the underlying mechanisms of material changes in the fusion environment, with the ultimate objective to aid development of advanced materials. The multiscale modeling methodology involved a hierarchical approach, integrating ab ...

We describe an approach to the high-resolution three-dimensional structural determination of macromolecules that utilizes ultrashort, intense x-ray pulses to record diffraction data in combination with direct phase retrieval by the oversampling technique. It is shown that a simulated molecular diffraction pattern at 2.5-? resolution accumulated from multiple copies of ...

Coherent x-ray diffraction microscope, with its spatial resolution limited only by signal-to-noise ratio, has paved a route to a generic nano-scope relieved from crystalline specimens and destructive sample preparation. We advanced it further as a versatile spectro-microscopy. By using stark contrast in x-ray scattering lengths in the vicinity of atomic absorption edges, we ...

A coherent description of the anomalous Hall effect is presented that is applicable to pure and disordered systems. This is achieved by an implementation of the Kubo-St?eda equation using the fully relativistic Korringa-Kohn-Rostoker method in combination with the coherent potential approximation. Applications to the pure ferromagnets Fe and Ni led to ...

A coherent description of the anomalous Hall effect is presented that is applicable to pure and disordered systems. This is achieved by an implementation of the Kubo-St?eda equation using the fully relativistic Korringa-Kohn-Rostoker method in combination with the coherent potential approximation. Applications to the pure ferromagnets Fe and Ni led to ...

The opportunity of detecting vibrationally excited ozone molecules using UV absorption spectroscopy in the Hartley band was studied. The proposed approach is based on comparing the experimentally measured absorption spectrum with the simulated one. For this purpose the absorption spectra for 35 lower vibrational states (1A1, v1v2v3) in the Hartley band were simulated from ab ...

We present the results of a computational investigation with ab initio procedures of the structure-energy and vibrational properties of silica clusters in a dielectric continuum with dielectric constant ?=3.8, through density functional theory/B3LYP gas phase calculations coupled with a polarized continuum model approach [integral equation formalism ...

We present the results of a computational investigation with ab initio procedures of the structure-energy and vibrational properties of silica clusters in a dielectric continuum with dielectric constant ?=3.8, through density functional theory/B3LYP gas phase calculations coupled with a polarized continuum model approach [integral equation formalism ...

Q/sub v/(J) transition energies of H/sub 2/ are measured for v = 0-4, J = 0-18 by coherent anti-Stokes Raman scattering (CARS) spectroscopy of rovibrationally excited H/sub 2/ from the H + HI ..-->.. H/sub 2/ + I reaction at high collision energies. The accuracy of the measurements reported here is 0.05 cm/sup -1/, limited by the bandwidth of the laser sources used. The ...