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...

... goals of this program have been to develop new, more effective methods for performing accurate ab initio electronic structure calculations and to ...

We have carried out extensive high quality ab initio electronic structure calculations of the ground

... the potential energy surface provided by modern electronic structure ... screening approach, to determine the equilibrium geometry and composition ...

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 other way, more ...

The goal of this research is to provide increased understanding of the chemistry and reactivity of pentavalent phosphorus compounds by analysis of structures and electronic structures obtained from ab initio molecular orbital calculations. Electronic stru...

We have carried out ab initio electronic structure calculations of the spin-orbit and rotation-orbit

The chemical structure and bonding of the hypermetallic Al5C and Al5C- species have been studied by photoelectron spectroscopy and ab initio calculations.

Examples of transition metal complexes containing dihydrogen ligands are investigated using ab initio electronic structure calculations employing effective core potentials. Calculated geometrical structures and relative energies of various forms of WL(sub...

General procedures for computing alloy phase equilibria from ab initio electronic structure calculations are reviewed and applied to the Al-Li phase diagram. Free energies were calculated by the cluster variation method (CVM) in the tetrahedron approximat...

Structural and thermal properties of small lithium clusters are studied using ab initio-based Monte Carlo simulations. The ab initio scheme uses a Hartree-Fock/density functional treatment of the electronic structure combined with a jump-walking Monte Car...

... goals of this program have been to develop new, more effective methods for perform in accurate ab initio electronic structure calculations and to ...

... known GAMESS suite of computer codes [2]. Accurate ab initio methods pro- ... to the systematic improvement of standard quantum-chemical methods ...

Research progress on an alternative method to ab initio variational and perturbative approaches for the electronic structure of molecules is described. Progress in the report year on the evaluation of (1) molecular properties, (2) energy derivatives with ...

In the present work we shall discuss recent advances in quantum chemical methodology that have improved the reliability of ab initio electronic structure ...

Results are reported from SDCI and CPF ab initio computations for the ground and low-lying states of

... substantial impact; these tools are now incorporated in many ab initio codes ... Most commonly used quantum chemical methods possess one or the ...

(either ab initio methods or basis sets) for electronic structure calculations, and a graph theory procedure for identifying instantaneous molecular fragment identities...

... softening of Al-based fcc alloys using ab initio Korringa-Kohn-Rostoker augmented-spherical-wave electronic structure calculations is discussed. ...

... Beta-(1-methyl-2-pyridinium) - alpha-cyano-4-styryldicyanomethanide was optimized using semi-empirical and ab initio quantum chemical methods ...

... previous grant period have been to develop new, more effective methods for performing accurate ab initio electronic structure calculations and to ...

... progress is reported in development of ab initio computational methods for the electronic structures of molecules employing atomic spectral-product ...

... progress is reported in development of ab initio computational methods for the electronic structures of molecules employing atomic spectral-product ...

For some simple, but nontrivial molecular systems, the interaction potentials are now well determined from ab initio electronic structure calculations ...

... Abstract : Electronic structure calculations using theoretical methods based on the linked-diagram theorem are reported for a series of dissociation ...

... previous grant period have been to develop new, more effective methods for performing accurate ab initio electronic structure calculations and to ...

Mar 1, 2011 ... Conformational Characteristics of Poly(tetrafluoroethylene) (PTFE) Based Upon Ab Initio Electronic Structure Calculations on Model Molecules ...

We present an algorithm for calculating the conformational thermodynamics of large, flexible molecules that combines ab initio electronic structure theory calculations with a torsional path integral Monte Carlo (TPIMC) simulation. The new algorithm overcomes the previous limitations of the TPIMC method by including ...

A combination of high-level ab initio electronic-structure calculations and empirical bond-additivity corrections are used to calculate thermochemical properties of gas-phase molecules. A self-consistent set of heats of formation for molecules in the SiH,...

A combination of high-level ab initio electronic-structure calculations and empirical bond-additivity corrections are used to calculate thermochemical properties of gas-phase molecules. A self-consistent set of heats of formation for molecules in the SiH, Si--H--Cl, Si--H--F, Si--N--H and Si--N--H--F systems is presented.

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. ...

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 ...

The possible role of electronic structure on observed phonon anomalies in high-temperature superconductivity transition-metal carbides is studied by means of accurate ab initio calculations of the conduction electron response function. From augmented-plan...

We describe an implementation of the benchmark ab initio electronic structure full configuration interaction model on the Intel Touchstone Delta. Its performance is demonstrated with several calculations, the largest of which (95 million configurations, 4...

Ab initio calculations of the electronic structure of Hn- and Hn+ clusters have been carried out using accurate Gaussian basis sets and with levels of theory up to fourth-order perturbation theory (MP4) and single and double excitation configuration inter...

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...

Progress is reported in development, implementation, and application of a spectral method for ab initio studies of the electronic structure of matter. In this approach, antisymmetry restrictions are enforced subsequent to construction of the many-electron...

Progress is reported in development, implementation, and application of a spectral method for ab initio studies of the electronic structure of matter. In this approach, antisymmetry restrictions are enforced subsequent to construction of the many-electron...

We present the result of ab initio modeling of the Ge(111)-(2 � 1) surface electronic structure in the presence of donor doping atom at certain position in the surface bilayer of (2 � 1) reconstruction. We briefly compare these results with the data of experimental low temperature STM investigations. ...

Progress are reported on: electronic structure of PdO, PtO, and AgO (band structure calculations); ab initio calculations of electronic structure of TiO{sub 2}(110) surface; and electronic structure of VO{sub 2} and TiO{sub 2} thin ...

Progress are reported on: electronic structure of PdO, PtO, and AgO (band structure calculations); ab initio calculations of electronic structure of TiO{sub 2}(110) surface; and electronic structure of VO{sub 2} and TiO{sub 2} thin ...

Progress are reported on: electronic structure of PdO, PtO, and AgO (band structure calculations); ab initio calculations of electronic structure of TiO(sub 2)(110) surface; and electronic structure of VO(sub 2) and TiO(sub 2) thin ...

Ab initio electronic-structure calculations are combined with empirical bond-additivity corrections to yield thermochemical properties of gas-phase molecules. A self-consistent set of heats of formation for molecules in the Si-H, Si-H-Cl, Si-H-F, Si-N-H a...

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 (various projects

Sch�ffel Ab initio Quantum Chemical Calculations with GAMESS-UK and GAUSSIAN90 Program Packages: ~ . , ISSN 0933-789X #12;Ab initio Quantum Chemical Calculations with GAMESS-UK and GAUSSIAN90 Program Packages Berlin 31 w Abstract Two commercial available molecular electronic ...

We present an ab initio quantum theory of the finite-temperature magnetism of iron and nickel. A recently developed technique which combines dynamical mean-field theory with realistic electronic structure methods successfully describes the many-body features of the one electron spectra and the observed magnetic ...

The reaction SiH4 + H(-) to SiH5(-) is investigated by employing ab initio quantum chemical techniques. With respect to silane and a hydride ion, a trigonal-bipyramidal form of SiH5(-) is found to be stable by 16.9 kcal/mol and a tetragonal-pyramidal form...

Electron energy-loss spectroscopy has been shown to be a powerful tool to determine the chemistry and the electronic structure at grain boundaries by analyzing the energy loss near edge structure (ELNES). This paper describes the ability of ab-initio density of state calculations to perform detailed quantitative analysis at interfaces.

We report the results of a large-scale ab initio simulation of an intergranular glassy film (IGF) model in ?-Si3N4. It is shown that the stress-strain behavior under uniaxial load in the model with prismatic surfaces and few defective bonds is very different from an earlier IGF model with basal planes. The results are explained by the fundamental ...

We use ab initio crystalline calculations to explore the role of iodine in determining the properties of 1,4-diiodobenzene. The results strongly suggest that the large halogen is an important or perhaps the dominant determinant of the ability of diiodobenzene to transport holes. We conjecture that the high mobility of diiodobenzene is due to a combination ...

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 ...

We have performed ab initio calculations of positron distribution, ACAR and lifetime in the quasi-one-dimensional organic conductor TTF-TCNQ. The electronic structure is obtained within the LDA, while the positron state is calculated either with the LDA or with the GGA. Except the positron lifetime, differences ...

Ab Initio electronic structure calculations using analytical energy derivative methods and automated potential energy surface walking techniques have been carried out on the tautomerization reaction path connecting formamide (F) H2N-CHO, through a transit...

Quantum mechanical-based (or ab initio) methods are used to predict the stability properties of materials although their application is limited to relatively simple systems in terms of structures and number of alloy components. However thermodynamics of complex multi-component alloys requires a more versatile approach afforded within the CALPHAD formalism. ...

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 ...

The structure of atomic clusters is investigated using methods of ab initio quantum chemistry in conjunction with scanning tunneling microscopy (STM). Gold sols are imaged via STM and their sizes characterized. Atomic resolution reveals facets, steps, and...

... Abstract : Using ab initio (6-31G(*)) and semiempirical (AM1, PM3) electronic structure calculations and force field (MM3) determinations, we have ...

The main goals of this program have been to develop new, more effective methods for perform in accurate ab initio electronic structure calculations and to use these methods for the prediction of molecular structure, bonding and reactivity, especially for ...

The main goals of this program have been to develop new, more effective methods for performing accurate ab initio electronic structure calculations and to use these methods for the prediction of molecular structure, bonding and reactivity, especially for ...

A relativistic pseudopotentional (RPP) for use in ab initio molecular electronic structure calculations is derived in the context of the relativistic effective core potential (REP) method of Lee et al. The resulting atom-specific RPP has salient features ...

The addition and abstraction reaction pathways on the potential energy surface for H + HCO have been characterized by an ab initio four electron, complete active space, self-consistent field electronic structure calculation. The elimination pathway to go ...

elucidate the properties of these molecular systems. Alkali-doped buckminsterfullerene(A$@) has been shownto

Group of Young Researchers 'Quantum Chemistry' (Dr. M. Dolg) The group of young researchers 'Quantum Chemistry' works on quantitative ab initio electronic structure calculations for properties of relativity and electron correlation are investigated and interpreted. A major area of research

The study of phase stability, including order-disorder phenomena and structural transformations, in substitutional alloys is of great theoretical and technological interest. The goal is to perform ab-initio calculations of thermodynamical properties of al...

Some of the approaches toward obtaining an understanding of alloy phase stability within the context of ab initio density functional theory are discussed. Recent results of calculations, using the concentration functional theory of Gyorffy and Stocks, of ...

Ab initio electronic structure calculations are performed to support and to help interpret the experimental work reported in the proceeding manuscript. The CCSD(T) approach, in conjunction with a large basis set, is used to compute spectroscopic constants...

The main goals in the previous grant period have been to develop new, more effective methods for performing accurate ab initio electronic structure calculations and to use these methods for the prediction of molecular structure, bonding and reactivity, es...

With the development of ab-initio molecular dynamics method, it has now become possible to study the static and dynamical properties of clusters containing up to a few tens of atoms. Here I present a review of the method within the framework of the densit...

We discuss a recent investigation of adatom behavior on the AISb(001) surface using first-principles electronic structure methods based on the density functional theory. For Al and Sb adatoms, we find a number of novel adatom structures that differ dramat...

ACES II, a new program system for ab initio electronic structure calculations is described. The strengths of ACES II involve the use of many-body perturbation theory (MBPT) and coupled-cluster (CC) theory for calculating the energy, geometry, spectra, and...

The main goals in the previous grant period have been to develop new, more effective methods for performing accurate ab initio electronic structure calculations and to use these methods for the prediction of molecular structure, bonding and reactivity, es...

Following remarks on the nature and limitations of ab initio solutions, recent advances in polyatomic electronic structure theory are discussed. The article closes with a discussion of the method of molecular-orbitals-ionic states. (Author)

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 ...

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 ...

Realistic electronic-structure calculations for correlated Mott insulators are notoriously difficult. Here we present an ab initio multiconfiguration scheme that adequately describes strong correlation effects involving Cu 3d and O 2p electrons in layered cuprates. In particular, the O 2p states giving rise to the Zhang-Rice band are ...

We have carried out self-consistent reaction field (SCRF) calculations on the bacteriochlorophyll (BChl) and bacteriopheophytin (BPh) molecules at the Hartree-Fock level using the ab initio electronic structure code PSGVB together with an accurate numerical Poisson-Boltzmann solver. These are by far the largest ...

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

A three-dimensional wavelet analysis is employed to develop a new formalism for electronic structure calculations. The wavelet formalism provides a systematically improvable and tractable description of electronic wave functions and overcomes limitations of conventional basis expansions. The potential power of the wavelet formalism for [ital ...

We discuss the application of the finite-element (FE) method to large-scale ab initio electronic-structure calculations in solids. The approach can be understood as an expansion method which uses a strictly local, piecewise-polynomial basis. Because the basis is polynomial in nature, the method is completely general and its convergence ...

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 ...

An accurate and efficient molecular alignment technique is presented based on first principle electronic structure calculations. This new scheme maximizes quantum similarity matrices in the relative orientation of the molecules and uses Fourier transform techniques for two purposes. First, building up the numerical representation of true ...

... 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,. ...

We have applied the ab initio path integral molecular dynamics simulation to study hydronium ion and its isotopes, which are the simplest systems for hydrated proton and deuteron. In this simulation, all the rotational and vibrational degrees of freedom are treated fully quantum mechanically, while the potential energies of the respective atomic ...

We have applied the ab initio path integral molecular dynamics simulation to study hydronium ion and its isotopes, which are the simplest systems for hydrated proton and deuteron. In this simulation, all the rotational and vibrational degrees of freedom are treated fully quantum mechanically, while the potential energies of the respective atomic ...

Structural and spectroscopic properties of hydrazine, H(2)N-NH(2), it being a floppy or fluxional molecule in a vacuum, are investigated by means of ab initio molecular dynamics, ab initio path integral molecular dynamics, and ab initio ring polymer molecular dynamics ...

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 ...

We review the recent research on the functional mechanisms of biological macromolecules using theoretical methodologies coupled to ab initio quantum mechanical (QM) treatments of reaction centers in proteins and nucleic acids. Since in most cases such biological molecules are large, the computational costs of performing ab ...

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 ...

The methodology of ab initio molecular dynamics, wherein finite-temperature dynamical trajectories are generated by using forces computed "on the fly" from electronic structure calculations, has had a profound influence in modern theoretical research. Ab initio molecular ...

The methodology of ab initio molecular dynamics, wherein finite-temperature dynamical trajectories are generated by using forces computed �on the fly� from electronic structure calculations, has had a profound influence in modern theoretical research. Ab initio ...

Structural and thermal properties of small lithium clusters are studied using ab initio-based Monte Carlo simulations. The ab initio scheme uses a Hartree-Fock/density functional treatment of the electronic structure combined with a jump-walking Monte Carlo sampling of ...

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 ...

We present a combined experimental and theoretical study on the Mn3d orbital occupation in orthorhombic DyMnO3 single crystals. We have observed a very strong polarization dependence in the MnL2,3 x-ray absorption spectra, indicative for a distinct anisotropic orbital occupation. Ab initio electronic-structure calculations ...

A detailed study of methods for generating the minimum energy path of a chemical reaction using ab initio electronic structure calculations is presented; the convergence with respect to step size of the geometry and energy along this path is studied with several algorithms. The investigations are extended to the ...

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 ...

Recent trends of ab initio studies and progress in methodologies for electronic structure calculations of strongly correlated electron systems are discussed. The interest for developing efficient methods is motivated by recent discoveries and characterizations of strongly correlated electron materials and by ...

The adsorption properties of transition-metal (TM) dimers on defect-free MgO(001) surfaces were studied from a series of ab-initio electronic structure calculations for late TM atoms of Cu, Ag, Au, Ni, Pd, and Pt. Two dimer configurations were considered: an upright dimer structure and a flat lying dimer structure. For Cu, Ag, Au, and ...

The electronic structure of a Ta2O5 insulator with oxygen vacancies is studied theoretically and experimentally. The ab initio calculations of ?-Ta2O5 are performed in terms of density functional theory using the generalized gradient (GGA) and GGA + U approximations. The electronic ...

Ab initio electronic-structure calculations are combined with empirical bond-additivity corrections to yield thermochemical properties of gas-phase molecules. A self-consistent set of heats of formation for molecules in the Si-H, Si-H-Cl, Si-H-F, Si-N-H and Si-N-H-F systems is presented, along with preliminary values for some Si-O-C-H ...

It is essential to know the arrangement of the atoms in a material in order to compute and understand its properties. Searching for stable structures of materials using first-principles electronic structure methods, such as density-functional-theory (DFT), is a rapidly growing field. Here we describe our simple, elegant and powerful approach to searching ...

Raman spectra of thin solid electrolyte films obtained by sputtering a Li2SO4 target in nitrogen plasma are measured and compared to ab initio electronic structure calculations for clusters composed of 28 atoms. Agreement between measured and calculated spectra is obtained only when some oxygen atoms are replaced ...

Ab initio molecular electronic structure theory has now progressed to the point where it is capable of making genuine contributions to the understanding of simple chemical reactions. Especially noteworthy examples are the elementary fluorine hydrogen reactions pertinent to the HF chemical laser. The reactions F + ...

Certain classes of temperature-composition binary alloy phase diagrams can now be computed in an ab-initio'' approach. No adjustable or experimentally fitted parameter is used. The expectation value of the energy is expressed in terms of an expansion of cluster probabilities, where the prefactors, the Effective Cluster Interaction, are related to the alloy ...

The results of ab initio slab calculations of surface relaxations, rumplings and charge distribution for the different terminations of the MgF2 (011) and (111) polar surfaces are presented and discussed. We have employed the computer code CRYSTAL with the Gaussian basis set and the hybrid B3PW exchange-correlation functional. Despite the ionic nature of ...

We present ab initio density functional investigations of the atomic and electronic structure of gallium nitride nanodots and nanowires. With increasing diameter, the average Ga-N bond length in the nanostructures increases, as does the relative stability (heat of formation), approaching the values for bulk GaN. As ...

Certain classes of temperature-composition binary alloy phase diagrams can now be computed in an ``ab-initio`` approach. No adjustable or experimentally fitted parameter is used. The expectation value of the energy is expressed in terms of an expansion of cluster probabilities, where the prefactors, the Effective Cluster Interaction, are related to the alloy ...

Employing ab initio calculations we predict that the magnetic states of hydrogenated diamond-shaped zigzag graphene quantum dots (GQDs), each exhibiting unique electronic structure, can be selectively tuned with gate voltage, through Stark or hybridization electric-field modulation of the spatial distribution and ...

It is essential to know the arrangement of the atoms in a material in order to compute and understand its properties. Searching for stable structures of materials using first-principles electronic structure methods, such as density-functional-theory (DFT), is a rapidly growing field. Here we describe our simple, elegant and powerful approach to searching ...

We present ab initio investigation of the electronic structure and magnetic properties of uranium monochal-cogenides: US, USe, UTe. The calculations were performed by using the recently developed LDA+ U+SO method in which both Coulomb and spin-orbit interactions have been taken into account in rotationally ...

General procedures for computing alloy phase equilibria from ab initio electronic structure calculations are reviewed and applied to the Al-Li phase diagram. Free energies were calculated by the cluster variation method (CVM) in the tetrahedron approximation for the fcc and bcc lattices and ordered superstructures. ...

The broad goal of this research program was to study excited state chemistry, and electronic energy transfer and chemical energy redistribution proceses, using the methods of ab initio electronic structure theory. Radioactive of metastable atomic species, electronic ...

It is now possible to calculate many properties including the energetics (total bond dissociation energies or heats of formation) of molecules containing light elements to high accuracy by using correlation-consistent basis sets, coupled cluster theory an...

structure of finite-length armchair carbon nanotubes has been studied using several ab-initio properties and the spatially-resolved electronic structure of finite-size nanotubes, quantum-chemical methods-band-gap polymers.12 To compensate for the weaknesses of the various quantum-chemical techniques, we utilized

The electronic structure of the model compounds U(NH(sub 2))(sub 3) and Np(NH(sub 2))(sub 3) is investigated with the aid of ab initio electronic structure techniques. The electronic ground states and equilibrium geometries of these complexes are determin...

The influence of Ti and Zr impurity atoms on the atomic and electronic structures of a mesoporous SiO2 matrix is ab initio simulated in a generalized gradient approximation. Energetically favorable positions of titanium and zirconium in the structure are revealed. The incorporation of Zr and Ti ions is shown to ...

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...

A new model Hamiltonian is developed to describe the ab initio energy differences of the nonisovalent alloy configurations based on the semiconductor electron counting rule. Monte Carlo simulations using this Hamiltonian show strong short range order of the GaN/ZnO alloy, which has significant effects on its electronic ...

... 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

As a part of the task of constructing the equivalent potential of water in order to obtain a reliable electronic structure for a protein, the equivalent potential of water for an arginine molecule was constructed by performing first-principles, all-electron, ab initio calculations. The process consisted of three ...

The energetic and electronic structure of bilayered graphene (BLG) with AA stacking arrangement on a SiO2 substrate is investigated in the presence of an electric field F of different intensities by ab initio density functional calculations. The AA-stacked bilayer graphene is stable on the SiO2 substrate in the ...

The electronic structure and chemical bonding of vitamin B12 (cyanocobalamin) and B12-derivative (methylcobalamin) are studied by means of X-ray emission (XES) and photoelectron (XPS) spectroscopy. The obtained results are compared with ab initio electronic structure ...

Ab initio calculations using SCF approach for and analysis of results of investigation of the electronic structure of the clusters RAn+:[L]k with rare earths or actinides were carried out for the clusters in solids and liquids. Theoretical results for the electronic ...

Properties of molecules solvated in ionic liquids (ILs) are strongly affected by solvent environment. For this reason, to give reliable results, ab initio calculations on solutes in ILs, including ions constituting ionic liquid itself, have to self-consistently account for the change of both electronic and classical solvation structure in ILs. Here, we ...

Atomic geometries, electronic structures, and magnetic moments of several metal clusters with 13 atoms are studied by ab initio density-functional calculations. The ground state structures of 13-atom metal clusters were previously assumed to be icosahedron, cuboctahedron, or decahedron. However, in this study, ...

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 ...

The atomic and electronic structure of uniformly and nonuniformly mixed Au-Co nanowires have been studied using the ab initio molecular dynamics method. The effect of elastic stretching/contraction deformations on the stability and electronic properties of mixed Au-Co nanowires has been studied. It is established ...

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 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 ...

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 ...

The electronic structure of the ScN and ScP molecules is a subject of controversy and turns out to be a challenging problem in quantum chemistry. We show that the ground-state electronic structure for both molecules depends critically on the choice of methods used which incorporate different ways of accounting for ...

We present results of electronic structure and magnetization measurements of Co:ZnO and Co:ZnO codoped with Al thin-film samples fabricated by solution-based methods together with ab initio electronic structure calculations. Electronic ...

With blooming experimental synthesis of various nanostructures out of many semiconductor materials, there is an urgent need to calculate the electronic structures and optical properties of these nanosystems based on reliable ab initio methods. Unfortunately, due to the O(N^3) scaling of the conventional ...

We present a general method for tracking molecular relaxation along different pathways from an excited state down to the ground state. We follow the excited state dynamics of cytosine pumped near the S(0)-S(1) resonance using ultrafast laser pulses in the deep ultraviolet and probed with strong field near infrared pulses which ionize and dissociate the molecules. The fragment ions are detected via ...

We present a general method for tracking molecular relaxation along different pathways from an excited state down to the ground state. We follow the excited state dynamics of cytosine pumped near the S0-S1 resonance using ultrafast laser pulses in the deep ultraviolet and probed with strong field near infrared pulses which ionize and dissociate the molecules. The fragment ions are detected via ...

This study investigates the electronic structure of Group IA cations intercalated into zeolites with the analcime (ANA) framework using ab initio periodic Hartree-Fock theory. The purpose of the study is to gain a better understanding of the role played by electron-donating species in zeolites in general, with ...

... 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 ...

...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...

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 ...

The structure and harmonic vibrational frequencies of Be sub 4 have been predicted using ab initio molecular electronic structure theory. A better than double zeta plus polarization (DZ+P) basis set was used in conjunction with self-consistent-field (SCF)...

Ab initio molecular electronic structure theory has been used to predict and characterize the remarkable species (HSiOOH)2. The dissociation energy to two silanoic acid monomers is predicted to be D sub 0 + 25 kcal/mol, twice that observed for the well-ch...

to describe the electron density and hence structure and mag- netic properties of iron. A signiFaraday Discuss., 1997, 106, 205�217 First principles calculations on crystalline and liquid iron Hauptstrasse 8-10/136, A-1040 V ienna, Austria Ab initio electronic structure calculations, based upon density

Van der Waals broadening coefficients for numerous spectral transitions and radiator-perturber pairs are estimated by semi-empirical methods. The results are verified by ab initio electronic structure calculations and available experimental data. At the same time this allows to establish the range of applicability ...

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...

New methods which avoid the repeated constructions of aggregate Hamiltonian matrices over antisymmetric basis states generally required in conventional calculations of adiabatic potential energy surfaces are reported for ab initio studies of the structure...

New methods which avoid the repeated constructions of aggregate Hamiltonian matrices over antisymmetric basis states generally required in conventional calculations of adiabatic potential energy surfaces are reported for ab initio studies of the structure...

with the number of non-f electrons,1 which we shall here call the effective valency. Compared with the LSD of the electronic structures of the Yb monopnictides. A. Bonding and valencies The calculated equilibrium volumes there being more ``normal'' band electrons in the trivalent Yb compounds . The trends in effective valency

Cesium iodide properties, both in the bulk and on (110) and (100) surfaces, are studied using density functional theory. The bulk lattice constant, bulk modulus, and elastic constants are in good agreement with the experimental values. The electronic band structure is also calculated, as well as the density of states. On the surfaces, relaxation of the atoms was performed, and the atomic geometry ...

Electronic structure of RNi{sub 5} (R=Nd, Sm, Eu, Gd) and SmCo{sub 5} compounds is calculated using the FLAPW method. The parameters of the effective crystal field hamiltonian acting on 4f states of the rare-earth atom are then determined from the nonspherical part of the crystal potential.

The atomic and electronic structures of Ge dimers adsorbed on top of a Si(100) flat surface has been investigated by first-principles molecular dynamics method. Four high-symmetry configurations have been considered and thoroughly relaxed. The most stable configuration for Ge dimers is found to be on the trough, in the middle of, and parallel to the ...

The effects of the 4f shell of electrons and the relativity of valence electrons are compared. The effect of 4f shell (lanthanide contraction) is estimated from the numerical Hartree-Fock (HF) calculations of pseudo-atoms corresponding to Hf, Re, Au, Hg, ...

Using the state-of-the-art ab initio electronic structure calculations, we explain why ?-Po prefers the simple cubic structure (it is due to the relativistic mass-velocity and Darwin terms), elucidate its extreme elastic anisotropy (this is an intrinsic property of the simple cubic crystal structure), and predict a ...

The rate constants for the forward and reverse reaction of OH + OH to form H(sub 2)O + O are calculated with variational transition state theory using an ab initio MCSCF electronic structure characterization of the reaction path on the two potential energ...

The broad goal of our research program was to study excited state chemistry, and electronic energy transfer and chemical energy redistribution processes, using the methods of ab initio electronic structure theory. Over the period of this grant we have stu...

Studies of ring-saturated pyrimidine base lesions are used to illustrate an integrated modeling approach that combines quantum-chemical calculations with molecular dynamics simulation. Electronic-structure calculations on the lesions in Isolation reveal s...

In this paper, the authors present theoretical evidence for ferromagnetism in Ru and Rh overlayers on Ag(001). These predictions are based on ab-initio, spin-polarized, electronic-structure calculations within the framework of the local spin-density approximation. For Tc, Ru, Rh, and Pd overlayers chemisorbed on Ag(001), only Ru and Rh exhibited ...

Nano-plasticity of thin single-wall carbon nanotubes under uniaxial compression is investigated through generalized tight-binding molecular dynamics (GTBMD) and ab-initio electronic structure methods. A novel mechanism of nano-plasticity of carbon nanotub...

We present ab initio LDA+DMFT calculations of CaVO3 perovskite near Mott transition. The calculated electronic structure and Fermi surface are in good agreement with an experimental data. The DMFT results are compared to conventional LDA band structure and an experimental data. The difference between the Fermi ...

-selected carbon nano molecular wires and rings were investigated on-line using a two-color laser spectroscopic method. The ab initio predicts that the linear structures of the pure carbon nano molecular wires-capped carbon wires could be semiconductors. 1. Introduction Molecular wires are proposed to be used

We applied the locally self-consistent multiple scattering (LSMS) method to the study Fe-based bulk amorphous metals. The LSMS method is an order- N approach to the electronic structure calculation for solid state materials based on density functional the...

We present results from ab-initio electronic-structure calculations of mechanical properties of the rhombohedral phase of vanadium reported in recent experiments (R Ia), and other predicted high-pressure phases (R Ib and bcc), focusing on properties relev...