with ultrasoft pseudopotentials as implemented in the VASP (Vienna Ab Initio Simulation Package) software

Using the coreless Hartree-Fock (CHF) pseudopotential approach we have generated pseudopotentials for the atoms K through Zn. Atomic calculations indicate that excitation energies and orbital energies using these pseudopotentials are in excellent agreement with ab initio Hartree-Fock ...

� � � SBOP +44 +10 786 796 EDTB -45 +16 416 432 MBPP: mixed-basis pseudopotential method CPMD: Car of this boundary using the ab initio, density functional theory based, mixed-basis pseudopotential method [39- denum and niobium. First, the ab initio mixed-basis ...

An approach is presented for the evaluation of the two distinct types of one-electron integrals arising from the ab initio pseudopotentials introduced by Kahn and Goddard. The integrals are shown to reduce to a sum over products of angular and radial integrals, the latter being approximated by power and asymptotic series combined with ...

... Abstract : The results of ab initio calculations based on the density-functional method and using the norm-conserving pseudopotentials for the ...

This bibliography lists the following reports: Optimized pseudopotentials, Ab-initio materials science and engineering using the molecular dynamics methods for total energy pseudopotential calculations, Oxygen complexes in Si, The enchanting properties of...

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.

We have studied structural and dynamical properties of Mg2Sn by employing an ab-initio pseudopotential method and a linear response scheme, within the generalised gradient approximation. The calculated lattice constant, bulk modulus and pressure derivative of bulk modulus are in agreement with previous ab-initio calculations and ...

We have studied structural and dynamical properties of Mg2Sn by employing an ab-initio pseudopotential method and a linear response scheme, within the generalised gradient approximation. The calculated lattice constant, bulk modulus and pressure derivative of bulk modulus are in agreement with previous ab-initio calculations and ...

The study of electrical resistivity of simple binary liquid alloy Na-K is presented as a function of concentration. Hard sphere diameters of sodium (Na) and potassium (K) are obtained through the inter ionic pair potentials evaluated using Troullier and Martins ab-initio pseudopotentials, which have been used to calculate partial structure factors S(q). ...

Recently presented nonrelativistic and quasirelativistic energy-adjusted ab initio pseudopotentials, semiempirical core polarization potentials and energy-optimized valence basis sets for the elements Hg to Rn have been applied in molecular calculations on selected hydrides of mercury through astatine and the fluorides of radon. ...

and pseudopotentials.14-16 Calculations are performed using the VASP (Vienna ab initio simulation package) software are modeled using the Vanderbilt-type ultrasoft pseudopotential included with the VASP software package.23 states. The normal ultrasoft versions of the pseudopotentials in the ...

-electronic temperature method of Alavi et al.7,8 FEMD implemented in the CPMD code.9 In this method, with a self of the image slab of Ni 111 is equal to about 12 �. A Troullier- Martins pseudopotential is used for oxygen and carbon,10 a local pseudopotential is used for hydrogen11 and for nickel the pseudopotential developed

We present a method for the computation of cohesive and structural properties of solids. The method is based on a local orbital description of the wavefunctions, an ab initio pseudopotential construction for the ion-core potential, and a local density tre...

Perturbative variational calculations of thermodynamic and structural properties of liquid metals, based on the use of ab initio and highly reliable nonlocal pseudopotentials for the electron-ion interactions and of the fluid of charged hard spheres as re...

The electronic structure of a vacancy in Al was calculated self-consistently using norm-conserving ionic pseudopotentials obtained from ab initio atomic calculations. A 27-atom-site supercell containing 1 vacancy and 26 atoms was used to simulate the envi...

Ab initio band structure calculations have been performed for the spin-orbit interaction effects at the top of the valence bands for GaAs and InSb. Relativistic, norm-conserving pseudopotentials are used with no correction made for the gaps from the local density approximation. The spin-orbit splitting at GAMMA and linear terms in the ...

The results of valence-only self-consistent field calculations on Hgn+ (n = 0, 1, 2) and HgHn+ (n = 0, 1) using nonrelativistic and quasirelativistic energy-adjusted ab initio pseudopotentials for Hg are compared with corresponding all-electron values from nonrelativistic (Hartree-Fock) and relativistic (Dirac-Fock) atomic as well as ...

scaling DFT code (see Peter Haynes) Other codes used in TCM for applications ffl CPMD � DFT ab initio? (MT/RN) ffl non�collinear spins in QMC (MT) ffl Pseudopotentials for many�body calculations (Lee, Mostofi, Di'eguez) Applications etc..(CASTEP, CPMD) ffl ab initio molecular dynamics ...

Ab-initio study of zone centre phonons in rare-earth hexaborides, MB6, has been made using self-consistent density functional method based on norm-conserving pseudo-potentials and numerical atomic orbitals as basis set. Calculated values of zone centre phonons are in fair agreement with the experimental results.

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 ...

Based on ab initio pseudopotential calculations, the results of investigations of the lattice dynamics of silver halides AgHal (Hal = Cl, Br, I) are presented. Equilibrium lattice parameters, phonon spectra, frequency densities and effective atomic-charge values are obtained for all types of crystals under study.

We present a theoretical investigation of the electronic structure of an InAs monomolecular plane inserted in bulk GaAs. Our calculations are based on the ab initio self-consistent pseudopotential method. Both electrons and holes are found to be strongly ...

Through the use of a molecular pseudopotential method, we determine the a approximate magnitudes of errors that result when electron affinity determinations of polar negative ions are made through ab initio calculations in which the use of a given basis set yields inappropriate values for permanent and induced dipole moments of the ...

#12;Parallel version of Quantum-ESPRESSO package CPMDCPMD CPMD ab initio total energy calculation electronic energy unique functional of the electron density n(r) � Vanderbilt ultrasoft pseudopotentials pseudopotentials � dimension of system cell � number of electrons and bands � cut-offs plane wave ...

�Oppenheimer approximation. QMC methods for hydrogen do not rely on pseudopotential approximations and treat electron performed using the Born� Oppenheimer molecular dynamics method, with the CPMD simulation pack- age (49 conserving nonlocal pseudopotential with a core radius of rc � 0.5 a:u. to represent hydrogen. The equations

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

The compression of Mg2SiO4, (?-forsterite, ?-wadsleyite and ?-ringwoodite) up to 24 GPa pressure is analysed with the help of two equation of state :first Birch-Murnaghan and second based on ab-initio pseudopotential approach. It is concluded that the EOS based on ab-initio pseudopotential approach show the ...

An ab initio study based on local-density-functional (LDF) theory is presented for the chemisorption of hydrogen on the Pd(111) surface. Our calculation uses the Vienna ab initio molecular-dynamics program (VAMP) based on (i) finite-temperature LDF, (ii) exact calculation of the electronic ground state and ...

We build an "all-electron" norm-conserving pseudopotential for boron which extends the use of ab initio molecular dynamics simulations up to 50 times the normal density rho0. This allows us to perform ab initio simulations of dense plasmas from the regime where quantum mechanical effects are ...

We build an 'all-electron' norm-conserving pseudopotential for boron which extends the use of ab initio molecular dynamics simulations up to 50 times the normal density {rho}{sub 0}. This allows us to perform ab initio simulations of dense plasmas from the regime where quantum ...

The structural, electronic and dynamic properties of cesium chloride, ZrRu and ZrZn were studied by employing an ab initio pseudopotential method and a linear response scheme, within the generalized gradient approximation. The calculated lattice constant, bulk modulus and first-order pressure derivative of the bulk modulus were ...

Quasirelativistic and nonrelativistic energy adjusted ab initio pseudopotentials for the elements Hg through Rn are presented together with corresponding optimized valence basis sets. Core-valence correlation is accounted for by semiempirical polarization potentials. Corrections to the point charge repulsion in the core-nucleus ...

We performed a comprehensive study of the static, dynamic, and electronic properties of liquid Pb at T=650K , ?=0.0309�?3 by means of 216-particle ab initio molecular dynamics simulations based on a real-space implementation of pseudopotentials constructed within density-functional theory. The predicted results and available ...

Recently developed ab initio pseudopotentials are employed to examine the molecular electronic structure of ZnF/sub 2/ in an LCAO-HF treatment. Comparison with a previous all-electron study reveals excellent agreement. Comparison with a pseudopotential treatment of ZnCl/sub 2/ shows, as expected, that the fluoride ...

-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 ...

Nonrelativistic and quasirelativistic energy-adjusted ab initio pseudopotentials substituting the 1s--3d core orbitals with corresponding spin--orbit operators for the rare earth elements Ce through Yb have been generated. Excitation and ionization energies from numerical pseudopotential calculations differ by less ...

Research completed during the period 1 Feb. 1990 - 28 Feb. 1994 is summarized in the following included papers: 'Ab Initio Statistical Mechanics of Structural Phase Transition'; 'Ab Initio Molecular Dynamics: Analytically Continued Energy Functionals and Insights into Iterative Solutions'; 'Ab ...

Ga- and As-terminated GaAs(100) surfaces are studied through first-principles density-functional pseudopotential calculations of the energies of surfaces with different stoichiometries and reconstructions. We predict structural transitions as a function of Ga and As chemical potentials within an experimentally accessible range which is shown to be fixed by the bulk energies of ...

Empirical many-body potentials of the glue-type have been constructed for the Al-Pb system using the force matching method. The potentials are fitted to experimental data, physical quantities derived from ab initio linear muffin-tin orbitals calculations and a massive quantum mechanical database of atomic forces generated using ultrasoft ...

developed by Perdew et al.30 and norm-conserving pseudopotentials. In static calculations carried out of anatase, we used a 4�4�2 Monkhorst�Pack mesh. The ab initio metadynamics was carried out using the CPMD code (CPMD V3.9 Copyright IBM Corp 1990�2004, Copyright MPI f�ur Festk�orperforschung Stuttgart 1997

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 electronic properties of PbTe nanocrystals (NCs) embedded in a CdTe matrix are investigated using an ab initio pseudopotential method and a repeated supercell approximation. The asymmetric distribution of polar dot-matrix interfaces leads to the presence of an electrostatic field within the NC region. The consequences of this field ...

The desorption potential energies of a hydrogen molecule from hydrogenated diamond C(100) surfaces have been calculated by the ab initio pseudopotential method.We found that a dihydride surface is less stable than a monohydride surface and that hydrogen desorption can be expected to occur from the dihydride instead of the monohydride ...

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 ...

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 ...

We have investigated the electronic structure of the quasi-one-dimensional organic conductor TTF-TCNQ [at room temperature (RT) and 100 K] and TSeF-TCNQ (RT), which have isomorphic crystal structure, by an ab initio plane-wave pseudopotential band calculation. To express the exchange and correlation energy for electrons, we used both ...

We present results for a comprehensive study of the static, dynamic and electronic properties of liquid Pb near melting by means of 216-particle ab initio molecular dynamics simulations based on a real-space implementation of pseudopotentials constructed within density-functional theory. The predicted results and available experimental ...

Nonrelativistic and quasirelativistic energy-adjusted ab initio pseudopotentials are presented for element 105 (hahnium, Ha) together with corresponding energy-optimized valence basis sets. The method of energy adjustment of pseudopotentials is extended to a two-component formalism and to multiconfiguration wave ...

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 ...

Ab initio molecular dynamics calculations are adapted to treat dense plasmas for temperatures exceeding the electronic Fermi temperature. Extended electronic states are obtained in a plane wave basis by using pseudopotentials for the ion cores in the local density approximation to density functional theory. The method reduces to ...

to Shirley,17 the peaks were deconvoluted using the CASA-XPS nonlinear least-squares software.18 III. ABCy /Si(001) alloy layers. The calculations were carried out using the Vienna ab initio simulation package VASP 19 which employs ultrasoft Vanderbilt-type pseudopotentials20 and a plane-wave basis set

pseudopotentials,14,15 as implemented in the highly-efficient Vienna ab initio simulation package (VASP).16,17 We atoms, respectively. TABLE IV. First principles (VASP�GGA) calculated equilib- rium lattice parameter. ACKNOWLEDGMENTS The authors wish to thank Dr. Axel van de Walle for his kind help on the use of the ATAT software

The ground-state properties of diamond are investigated using an ab initio density-functional pseudopotential scheme. The calculated equilibrium lattice constant, cohesive energy, and bulk modulus are in excellent agreement with experiment. Unlike Si and Ge, a double hump is found in the valence-electron charge density along the ...

The electronic and ionic structure of primary defects in silicon carbide (SiC) is studied using ab-initio plane-wave pseudopotential methods. The studied effects include the carbon and silicon vacancy, the silicon and carbon antisite, the antistructure-pa...

. All ab initio molecular dynamics simulations were performed with the CPMD program.13 Density func and Ernzerhof.14 Core electrons on all atoms were represented by norm- conserving pseudopotentials15). 13 J. H�utter et al., CPMD, Copyright IBM Z�urich Research Laboratory and MPI f�ur Festk

-functional theory calcula- tions, as implemented in the Vienna ab initio simulation package VASP code,37 are used are performed with DMol3 module of the Accelrys MATERIALS STUDIO software package. A double numerical basis set are described by the ultrasoft Vanderbilt pseudopotentials39 provided in the VASP program.37 The cut- off ...

The system consisting of two diamond (001) surfaces in contact was studied by means of plane-wave/pseudopotential density functional calculations. Different hydrogen coverages, ranging from fully hydrogenation to bare surfaces, were considered. The adhesion energy was calculated as a function of both the separation and the lateral displacement of the two surfaces. The effects ...

It is predicted that among the fcc, bcc, hcp, simple cubic, and ..beta..-tin phases, diamond will first transform to the simple cubic phase under a hydrostatic pressure of 23 Mbar. The absence of p electrons in the core causes remarkably strong sp/sup 3/ bonding in diamond. This stabilizes diamond against the other five phases under high pressures. The study is carried out using ...

Scientists have long pondered why the simple cubic structure is so rarely seen in nature. Only one element forms the simple cubic structure: polonium. There are `proofs' dating back to 1954 that the simple cubic lattice should be unstable. We will attempt to address the question of why polonium takes the simple cubic structure by means of ab initio ...

Using ab initio pseudopotentials the properties of electrons, phonons and electron-phonon interactions in highly compressed Si have been computed. In particular, the hexagonal phases have been predicted to be superconducting by this calculation. The superconducting transition temperature for hexagonal Si has been measured for pressures ...

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 ...

The electronic properties of the ionic insulator sodium nitrite (NaNO(sub 2)) have been studied using the self-consistent, ab-initio pseudopotential-density functional method. The Kohn-Sham equations of density functional theory were solved for the electr...

We report ab initio calculations of the electronic and magnetic properties of small Co clusters. We performed pseudopotential-based and all-electron calculations. In view of the ``unwritten theorem'' that electron localization enhances the electronic correlations, we have also considered the LDA+U functional, which is tailored for the ...

A large number of today�s ab initio calculations, in particular in solid-state physics, are based on density-functional theory using first-principles pseudopotentials. This approach, initially developed for the ground state, is nowadays widely used as a starting point for the calculation of excited-state properties, as, for instance, ...

Ab initio calculations of cohesive properties, elastic constants, and phonon dispersions for CoSi2 were performed by means of the Vienna ab initio molecular-dynamics package (VAMP), which makes use of ultrasoft pseudopotentials. In addition, the all-electron full-potential linearized ...

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

Pseudopotential {ital ab} {ital initio} calculations are performed for three high-pressure phases of sulfur (bco, {beta}-Po, and bcc). These calculations yield a value of around 550 GPa for the transition pressure of the {beta}-Po to bcc transformation; however, we do not reproduce the reported bco to {beta}-Po phase transition. {ital ...

Detailed ab initio studies on the electronic structure and optical properties of crystalline strontium azide and barium azide have been performed using density functional theory (DFT) within the generalized gradient approximation (GGA). Relaxed crystal structures compare well with experimental data. An analysis of electronic structure, charge transfer, and ...

In the present work, all adiabatic potential energy curves, spectroscopic constants and dipole moments of CaH+ molecular ion dissociating below the ionic limit Ca2+H- are presented. These curves are determined by an ab initio approach involving a non-empirical pseudo-potential for the Ca core, core-valence correlation accounted in ...

Structural phase transitions of GeTe are studied with the use of the ab initio pseudopotential density-functional method. Transition pathways and pressures for NaCl-to-CsCl structures are investigated considering three different paths, namely, the Watanabe, Tol�dano, and modified Buerger pathways. Structural and electronic properties ...

By combining ab initio all-electron localized orbital and pseudopotential plane-wave approaches we report on calculations of the electron affinity (EA) and the ionization potential (IP) of (5, 5) and (7, 0) single-wall carbon nanotubes. The role played by finite-size effects and nanotube termination has been analysed by comparing ...

We present a fully [ital ab] [ital initio] calculation of the thermodynamic properties for silicon within the quasiharmonic approximation, making use of volume-dependent phonon frequencies obtained from pseudopotential local-density calculations. The temperature dependence of the thermal-expansion coefficient, specific heat (at ...

A systematic study of ground state properties of cubic (3C) and hexagonal (6H, 4H, 2H) polytypes of normal (nonnitride) III-V compounds is reported using well-converged density-functional calculations within local density approximation, ab initio pseudopotentials, and projector-augmented wave method. Equilibrium results are obtained ...

We present results for several structural and dynamical properties of the liquid Li1-xNax alloy. The study has been carried out by means of the orbital-free ab initio molecular dynamics method, combined with local ionic pseudopotentials constructed within the same framework. We obtain good agreement with the available experimental ...

Interaction potentials of the iodine atom, atomic cation, and anion with light rare-gas atoms from He to Ar are calculated within the unified ab initio approach using the unrestricted coupled-cluster with singles and doubles and perturbative treatment of triples correlation treatment, relativistic small-core pseudopotential, and an ...

Results are presented of a fully ab initio calculation of impact ionization rates in GaAs within the density functional theory framework, using a screened-exchange formalism and the highly precise all-electron full-potential linearized augmented plane wave method. The calculated impact ionization rates show a marked orientation dependence in k space, ...

The millimeter-wave rotational spectrum of ethanetellurol has been recorded and assigned for the first time. The spectroscopic study has been complemented by high level ab initio calculations. Geometries, total electronic energies, and harmonic vibrational frequencies have been determined at the MP2 level. A small-core relativistic ...

Electronic structure methods based on density-functional theory, pseudopotentials, and local-orbital basis sets offer a hierarchy of techniques for modeling complex condensed-matter systems with a wide range of precisions and computational speeds. We analyze the relationships between the algorithms for atomic forces in this hierarchy of techniques, going from empirical ...

The static and dynamic properties of liquid Sn at two di?erent thermodynamic states have been studied from the Orbital Free Ab-Initio Molecular Dynamics (OFAIMD) simulation method. This method is based on the density functional theory (DFT) of Hohenberg and Kohn. The exchange and correlation interaction is described here with the local density approximation (LDA). We, in this ...

Ab-initio total energy pseudopotential calculations were performed on talc and pyrophyllite to assess the success of the method in determining the structure of layered silicates. The calculated relative atomic coordinates were in good agreement with experiment. Further calculations were undertaken to determine the probable position of water in hydrated 10 ...

Ab initio lattice dynamics based on linear response method are performed for high pressure phase of yttrium to describe electron-phonon coupling and subsequent superconducting behavior. The critical temperature Tc in fcc-Y increases monotonically with pressure up to 9.25 K at 31 GPa, which is quantitatively in excellent agreement with two quasihydrostatic ...

The hyperfine coupling of the electron spin to the nuclear spins nearby contains information on the local environment such as the chemical composition, distances, or bond angles. A correct interpretation of this information requires a comparison to a theoretical model. In this work, we employ spin-density-functional theory and ab initio ...

We report what is to our knowledge the first ab initio study of the singly charged divacancy in silicon to make direct comparison with mechanical response experiments. This novel approach, which does not rely upon energy differences which have proven to be too small to resolve reliably within the uncertainties of the local spin-density approximation ...

STM images of carbon nanotubes always contain the influence of both the geometrical and electronic structure. In our several former papers we explored in detail the contributions of the geometrical factors including the effects caused by the STM tip curvature, point contacts between the tip and the nanotube, charge spreading along the nanotube during tunneling, and so on with a jellium model ...

We present results of first-principles atomic and electronic structure calculations for a number of silver halides. For a most accurate treatment of the halides we employ our self-interaction and relaxation-corrected pseudopotentials together with Gaussian-orbital basis sets. Our results for the rocksalt-structure crystals AgCl and AgBr, as well as for the wurtzite and ...

... 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,. ...

Achieving multi exciton generation (MEG) in semiconducting nanocrystals may lead to overcome the well-known Shockley-Queisser limit when building semiconductor-based solar cells. A thourough, theoretical understanding of the experiments that reported MEG in e.g. Si and PbSe nanocrystals, is still missing and could significantly contribute to clarify the several controversial results in the field. ...

The ab initio pseudopotential method is used to study transient-enhanced-diffusion (TED) related processes. The electronic degrees of freedom are included explicitly, together with the fully self-consistent treatment of the electron charge density. A large supercell and a fine k-point mesh are used to ensure numerical convergence. Such ...

Multiconfiguration self-consistent-field calculations have been carried out on the X /sup 1/S/sup +/ and a /sup 3/S/sup +/ states of LiH, NaH, KH, RbH, and CsH, and on the X /sup 2/S/sup +/ states of their respective anions. Pseudopotentials, including core polarization terms, have been used to replace the core electrons, resulting in simple two- and three-electron ...

In tris(phosphine)(sulfur dioxide)nickel(0) complexes the mode of {eta}{sup 1}-coordination of SO{sub 2} depends in a very sensitive way on the nature of the phosphine coligands, i.e., their electronic and steric influences. MO calculations on the pseudopotential ab initio level show that the experimental structure ({eta}{sup ...

The levels associated with the lowest {sup 7}F and {sup 5}D terms of Am{sup +3} have been calculated using ab initio spin-orbit configuration interaction techniques. A series of configuration interaction calculations were carried out that include significant amounts of single and double excitations and with two different ...

The phase transition of NaH from NaCl- to CsCl-type structure is investigated by an ab initio plane-wave pseudopotential density functional theory method with the norm-conserving pseudopotential scheme in the frame of the generalized gradient approximation correction; the isothermal bulk modulus and its first and ...

Theoretical investigations of color centers in alkali azides included a nonlocal pseudopotential calculation for the F center in NaN/sub 3/, and an ab-initio molecular orbital calculation with configuration interaction for N4- in KN/sub 3/ (in progress). Supporting experiments correlating polarized optical and ESR spectra in NaN/sub 3/ suggests ...

We present an ab initio study of the effect of spin-orbit coupling on the dynamical properties of the Tl(0001) surface as well as on the electron-phonon interaction at the surface. The calculations based on density-functional theory were carried out using a linear response approach and a mixed-basis pseudopotential method. It is shown ...

Superhard cubic boron-carbonitrides (c-BC2N) are studied with the use of the ab initio pseudopotential density functional method. The total energy, lattice constant, bulk and shear moduli, and electronic band structures as well as the electron density of states are calculated for all the possible c-BC2N structures in an eight-atom ...

Superhard cubic boron-carbonitrides (c-BC{sub 2}N) are studied with the use of the ab initio pseudopotential density functional method. The total energy, lattice constant, bulk and shear moduli, and electronic band structures as well as the electron density of states are calculated for all the possible c-BC{sub 2}N structures in an ...

Using the ab initio pseudopotential density functional method, we investigate the functionalization of halogen molecules into graphene-based nanostructures with zigzag and armchair edges. We find that halogen molecules adsorb through chemisorption on the zigzag edge carbon atoms with a binding energy of ~1-5 eV, in sharp contrast to ...

The structural stability of the rhombohedral and simple cubic phases is studied for the group-VA elements. Using an ab initio pseudopotential total-energy method, the calculated phonon frequencies for the longitudinal acoustic mode at the corner of the simple-cubic Brillouin zone are found to soften. This suggests that all group-V ...

Using an ab initio pseudopotential approach, the pressure dependence of the electron-phonon interaction parameter lambda and the phonon frequencies for metallic hexagonal phases of silicon is calculated. With changing pressure lambda is found to go first through a minimum and then reach its maximum value near the phase transition from ...

An empirical model and an ab initio calculation of the bulk moduli for covalent solids are used to suggest possible new hard materials. The empirical model indicates that hypothetical covalent solids formed between carbon and nitrogen are good candidates for extreme hardness. A prototype system is chosen and a first principles ...

Experimental Mg K-edge XANES spectra were obtained for crystals and synthetic glasses. To interpret the experiments, two different ab initio XANES calculation methods were employed. The first one is based on multiple-scattering calculations and muffin-tin potentials (FEFF package). The second uses a plane-wave basis set, norm-conserving ...

Experimental Mg K-edge XANES spectra were obtained for crystals and synthetic glasses. To interpret the experiments, two different ab initio XANES calculation methods were employed. The first one is based on multiple-scattering calculations and muffin-tin potentials (FEFF package). The second uses a plane-wave basis set, norm-conserving ...

The ideal shear strength of transition metal carbides and nitrides is calculated with the use of the ab initio pseudopotential density functional method. The microscopic mechanism that limits the ideal strength is studied using full atomic and structural relaxation and the results of electronic structure calculations. It is shown that ...

pseudopotential ab initio package, http://hpcrd.lbl.gov/ linwang/petot/petot.html, 2004. 18 #12;[8] http://cms.mpi.univie.ac.at/vasp] http://www.psc.edu/general/software/packages/lsms/. [11] http code VASP [8]) to simulate the 13,824-atom system discussed in this paper would require between 4

results more reliable we have used different ab initio pack- ages FHIMD98,33 CPMD,34 and PWSCF 35 local-density approach . We have used norm-conserving pseudopotentials,39 with s and p nonlocality for C used the code CPMD, versions 3.0-3.5, developed by J. Hut- ter et al., at MPI fu�r Festko

experiments seem to suggest antiferromagnetic behavior.8,9 The latest experimental studies, that we are aware and pseudopotential9,14,15 methods, all based on the local spin density LSD approximation. Both the Zener model description and the LSD-based ab initio calculations are in agreement regarding the crucial role played

The electronic structure of a vacancy in Al was calculated self-consistently using norm-conserving ionic pseudopotentials obtained from ab initio atomic calculations. A 27-atom-site supercell containing 1 vacancy and 26 atoms was used to simulate the environment of the vacancy. A vacancy formation energy of 1.5 eV was also calculated ...

The package fhi96md is an efficient code to perform density-functional theory total-energy calculations for materials ranging from insulators to transition metals. The package employs first-principles pseudopotentials, and a plane-wave basis-set. For exchange and correlation both the local density and generalized gradient approximations are implemented. The code has a low ...

Possible high-pressure phases of Al are examined by comparing the total energies for three structures: fcc, bcc, and hcp. The energies are calculated using the density-functional formalism and the ab initio self-consistent pseudopotential approach. At zero pressure, the most stable structure is the fcc structure in agreement with ...

Properties of neat liquid formamide (HCONH2) have been studied by the combination of gradient-corrected density-functional theory, norm-conserving pseudopotentials, and the adaptive finite-element method. The structural and dynamical quantities have been calculated through molecular dynamics simulations under the Born-Oppenheimer approximation. Satisfactory agreement with ...

The Ca* + CH3F --> CaF + CH3 reaction was photoinduced in 1:1 Ca...CH3F complexes formed in a supersonic expansion. The transition state of the reaction was explored by monitoring the electronically excited product, CaF, while scanning the laser that turns on the reaction. Moreover, the electronic structure of the Ca...FCH3 system was studied using ab ...

The ab initio molecular-dynamics formalism of Car and Parrinello is extended to preserve the locality of the orbitals. The supplementary term in the Lagrangian does not affect the nuclear dynamics, but ensures "on the fly" localization of the electronic orbitals within a periodic supercell in the Gamma-point approximation. The relationship between the ...

The ab initio molecular-dynamics formalism of Car and Parrinello is extended to preserve the locality of the orbitals. The supplementary term in the Lagrangian does not affect the nuclear dynamics, but ensures ``on the fly'' localization of the electronic orbitals within a periodic supercell in the ?-point approximation. The relationship between the ...

There are many large-scale nanoscience problems that require ab initio accuracy total energy calculations and atomic relaxations. Unfortunately, the traditional direct ab initio method scales as O(N^3), where N is the number of atoms in the system, and most of the O(N) methods studied in the last decade have ...

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 ...

We calculate the dynamic structure factor S(k,?) of liquid Ge (l-Ge) at temperature T=1250 K, and of amorphous Ge (a-Ge) at T=300 K, using ab initio molecular dynamics. The electronic energy is computed using density-functional theory, primarily in the generalized gradient approximation, together with a plane-wave representation of the wave functions and ...

We present a computer package designed to generate and test norm-conserving pseudo-potentials within Density Functional Theory. The generated pseudo-potentials can be either non-relativistic, scalar relativistic or fully relativistic and can explicitly include semi-core states. A wide range of exchange correlation functionals is included. Catalogue ...

SCF ab initio calculations at the 6-31G level have been used to investigate the structure of several aggregates simulating some of the proton donor sites within faujasite-type zeolites. The Si(OH)/sub 4/, H/sub 3/SiOHAlH/sub 3/, and (OH)/sub 3/SiOHAl(OH)/sub 3/ clusters have been successively examined. Deprotonation energies and charge distribution are ...

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

Due to recent advances in methods and computers, the accuracy of ab calculations has reached a point

The geometrical parameters and quantum mechanical force fields (QMFF's) of 3,3-dimethyl-1-(trimethylplumbyl)cyclopropene (I), 3,3-dimethyl-1-(t-butyl)cyclopropene (II), 3,3-dimethyl-1-(trimethylsilyl)cyclopropene (III), 3,3-dimethyl-1-(trimethylgermyl)cyclopropene (IV), and 3,3-dimethyl-1-(trimethylstannyl)cyclopropene (V) were calculated at the pseudopotential (HF/SDDAll) ...

The authors present a parallel implementation of the previously developed folded spectrum method for empirical pseudopotential electronic calculations. With the parallel implementation the authors can calculate a small number of electronic states for systems of up to one million atoms. A plane-wave basis is used to expand the wavefunctions in the same way as is commonly used ...

Surface collective charge excitations are investigated for Be(0001) surface with explicit inclusion of band structure effects evaluated within an ab initio pseudopotential approach. The strong impact of beryllium surface band structure on the collective excitations at this surface is shownE Instead of a single-peak structure in the ...

Phonons in single crystals of PrFeAsO1?y are investigated using high-resolution inelastic x-ray scattering and ab initio pseudopotential calculations. Extensive measurements of several samples (?0, 0.1 and 0.3) at temperatures spanning the magnetic ordering temperature (TN�145 K for ? 0) and the superconducting transition temperature ...

Physics at the nanoscale has emerged as a field where discoveries of fundamental physical effects lead to a greater understanding of the solid state. Additionally, the field is believed to have a large potential for technological applications, which has driven a high pace of experimental achievements in fabrication and characterization. From the side of theoretical modeling�so successful in ...

Physics at the nanoscale has emerged as a field where discoveries of fundamental physical effects lead to a greater understanding of the solid state. Additionally, the field is believed to have a large potential for technological applications, which has driven a high pace of experimental achievements in fabrication and characterization. From the side of theoretical modeling-so successful in solid ...

We have tested a new and general approach for the theoretical study of unimolecular decomposition. By combining the power of the ab initio molecular dynamics (MD) and ab initio molecular orbital (MO) methods, our approach requires no prior experimental knowledge or intuitive assumptions about the decomposition. ...

... 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...

The elastic moduli of magnesium (Mg) have been evaluated as functions of pressure and temperature through the use of fluctuation formulas and Monte Carlo simulation. The simulations employ {ital ab initio} interatomic potentials for Mg derived from generalized pseudopotential theory and used previously to predict the ...

The developments of nonlinear optical (NLO) crystals in the last decade are reviewed from two aspects. In the theoretical part, on the ab initio plane-wave pseudopotential energy method, calculation of the optical responses, including the second harmonic generation coefficients, a computer-program package, and a real-space atom-cutting ...

We have carried out an ab initio molecular-dynamics simulation for liquid Li0.61Na0.39 alloys at four temperatures above and below the phase-separating temperature and have investigated the structure and electronic states to understand the microscopic mechanism of the phase separation. The calculated concentration-concentration structure factors S CC(k) ...

Atomic and electronic structures of the electronically magic Na{sub 59}{sup +} cluster are investigated using density functional theory and an ab initio pseudopotential. Two atomically closed-shell structures are found, but none of these 'double-magic' structures is the global ground state at T=0. Simulated annealing ...

The electronic excitation spectrum in baryllium, magnesium, cadmium and mercury chalcogenides has been calculated by means of the ab-initio GW approximation using norm-conserving pseudopotentials, plane-waves or mixed-basis expansions, and including the spin-orbit interaction. Both real and imaginary parts of self-energy have been obtained, thus giving ...

We present a methodology used to generate interatomic potentials fitted on results of ab initio calculations. Our aim is to obtain models suitable for large-scale simulations in ionic solids. We fitted a potential based on the rigid-ion model in order to investigate the high-temperature properties of lithium oxide. Density-functional theory calculations ...

A brief review of electronic structure methods used to calculate the properties of self-trapped excitons in silica is presented. The computational focus has been on silica crystalline systems because amorphous systems, such as fused silica, pose a significant technical challenge. The tremendous growth in speed of computer processors and available memory has led to a new generation of ...

We report a comparison between experimental and theoretical electronic transition dipole moment values for the 7Li2 A 1?u+-X 1?g+ system. The experimental results are based on measuring the absolute magnitude of the transition dipole matrix elements from Autler-Townes splitting of rovibrational transitions for different R-centroid values. The ab initio ...

We report a comparison between experimental and theoretical electronic transition dipole moment values for the (7)Li(2) A (1)Sigma(u) (+)-X (1)Sigma(g) (+) system. The experimental results are based on measuring the absolute magnitude of the transition dipole matrix elements from Autler-Townes splitting of rovibrational transitions for different R-centroid values. The ab ...

An ab initio approach is developed for calculation of low-lying excited states in Ln(3+) complexes with organic ligands. The energies of the ground and excited states are calculated using the XMCQDPT2/CASSCF approximation; the 4f electrons of the Ln(3+) ion are included in the core, and the effects of the core electrons are described by scalar ...

We report on first-principles studies to investigate the zone-centre optical phonons and polaron properties in zinc-blende AlxGa1-xN alloys over the whole compositional range. The calculations are performed using ab initio pseudopotential approach based on the density functional perturbation theory under the virtual crystal ...

We report a study on several static, dynamic, and electronic properties of liquid Hg at room temperature. We have performed ab initio molecular dynamics simulations using Kohn-Sham density functional theory combined with a nonlocal ultrasoft pseudopotential. The calculated static structure shows good agreement with the available ...

The first three ionization potentials of americium are calculated using ab initio spin-orbit configuration interaction techniques. These results are favorably compared to available experimental and previous theoretical work. The lowest two ionization potentials are accurately determined using wave functions constructed as simple single and double ...

Atomistic simulation of a vacancy-assisted dopant diffusion in silicon needs details of the dopant-vacancy interaction, i.e., the potential as a functional of dopant-vacancy separations. In this paper, the authors present a detailed study on the energetics of As-vacancy reaction in silicon and the lattice distortions surrounding the As-vacancy defect by using an ab ...

... ADP023770. Title : ab-Initio Molecular Dynamics Simulations of Molten Ni-Based Superalloys. Descriptive Note : Conference paper. ...

... 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 ...

... Title : Ab-Initio Molecular Dynamics Simulations of Molten Ni-Based Superalloys. Descriptive Note : Conference paper (preprint). ...

... 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. ...

... 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 ...

... 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 ...

... Title : Ab Initio Calculation of Vibrational Circular Dichroism Spectra Using Accurate Post-Self-Consistent-Field Force Fields: trans-2,3 ...