There has been only a limited amount of experimental investigation of the photoabsorption and photoionization processes of the OH radical. In this paper, we present ab initio calculations of photoionization cross sections and photoelectron angular distrib...
National Technical Information Service (NTIS)
Using a theoretical quantum chemical approach, we .... completion of the ab initio calculation of the Rydberg and valence potential ...
NASA Website
Starting from the 1980s and onwards, Valence Bond theory has been enjoying renaissance that is characterized by the development of a growing number of ab initio methods, and by many applications to chemical reactivity and to the central paradigms of chemistry. Owing the increase of computational power of modern computers and to ...
PubMed
binding sites i.e., one valence- and one dipole-binding center is studied using ab initio electronic enough to overcome the Coulomb repulsion produced by the valence-bound electron, the dianion can of the molecular dipole, and the second excess electron bound by valence interactions to another ...
E-print Network
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
In a previous contribution, we outlined a method for predicting (hydr)oxy-acid and oxide surface acidity constants based on three main factors: bond valence, Me O bond ionicity, and molecular shape. Here, electrostatics calculations and ab initio molecular dynamics simulations are used to qualitatively show that Me O bond ionicity ...
NASA Astrophysics Data System (ADS)
The major advance made in the work supported under this Grant has been the development of what appears to be a very generally applicable procedure for carrying out ab initio calculations employing only the valence orbitals of atoms, molecules and presumab...
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 ...
Ab initio calculations of valence shell ionization potentials have shown that orbital relaxation and correlation differences usually make contributions of comparable magnitude. In marked contrast to this observation is the situation for deep core ionizati...
In a previous contribution, we outlined a method for predicting (hydr)oxy-acid and oxide surface acidity constants based on three main factors: bond valence, Me?O bond ionicity, and molecular shape. Here electrostatics calculations and ab initio molecular dynamics simulations are used to qualitatively show that Me?O bond ionicity ...
Energy Citations Database
We present experimental and ab initio theoretical determination of the dynamics of valence electrons in potassium by investigating the dynamical structure factor at nonvanishing momentum transfers. The spectra show large deviations from a jellium-type behavior due to the presence of d -type states above the Fermi level. In particular, ...
{ital Ab} {ital initio} averaged relativistic effective core potentials (AREP) and spin--orbit (SO) operators are reported for the elements Cs through Rn. Two sets have been calculated for certain elements to provide AREPs with varying core/valence space definitions thereby permitting the treatment of core--valence ...
Molecular mechanics valence force field parameters for the sulfonamide group, SO[sub 2]NH, have been derived from ab initio calculations at the RHF/6-31G* level of theory. The force field parameters were designed to be used in conjunction with existing parameters from the MM2/MMP2 force field. The new parameters are demonstrated to ...
... This study involves: Ab-initio crystal orbitals and polymer orbitals; Ab-initio coupled cluster program; Ab-initio quantum chemical calculations and ...
DTIC Science & Technology
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 ...
DOE Information Bridge
The protonation scheme and the hydrogen bond connectivity in the structure of jennite were investigated by ab initio molecular dynamics simulations. The calculated statistics of hydrogen bonds at ambient conditions is consistent with the protonation scheme proposed by Bonaccorsi et al. (2004) based on the bond valence theory. The ...
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. ...
Potential energy curves for electronic states of Hg/sub 2/ and TlHg are presented and analyzed. They are derived using large scale configuration interaction procedures for the valence electrons, with the core electrons represented by ab initio relativistic effective potentials. The effect of spin-orbit coupling are investigated for the ...
The ability of simple levels of ab initio molecular orbital theory to describe with reasonable accuracy the energetics of isotopic exchange processes is demonstrated. Three levels of ab initio molecular orbital theory have been surveyed. The first two levels are single-determinant Hartree-Foch methods utilizing the ...
A model for the evolution of conduction and valence bands of IIIA-VA (InAs, GaAs, and InP) semiconductors under (001) biaxial strain is developed. The model is based on the ab initio calculations which take into account finite strain dependent relaxation of the reference levels. The results of ab ...
An ab initio nonorthogonal valence bond program, called XMVB, is described in this article. The XMVB package uses Heitler-London-Slater-Pauling (HLSP) functions as state functions, and calculations can be performed with either all independent state functions for a molecule or preferably a few selected important state functions. Both ...
A quantitative characterization of the Rydberg and valence singlet electronic states of acetylene lying in the 5-10.7 eV region is performed by using large-scale ab initio calculations. A special attention is paid on the comparison between the present calculations and Mulliken's concepts for Rydberg states, based on single-electron 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 ...
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 ...
... 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 report on large ab initio calculation for the 4s^2- 4s4p transitions in the Zinc-like sequence, using the multi-configuration Dirac-Hartree-Fock method. Results for fine-structure energy levels, the wavelengths, transition rates and lifetimes between Z = 70 (Yb) and Z= 92 (U) are presented and compared with other theories and experiments. The calculated ...
... Title : AB Initio Study of the Electronic Magnetic Circular Dichroism ... functions are determined using as initio quantum chemical techniques including ...
Valence electronic excitation spectra are calculated for the H(2)O���Br(2) complex using highly correlated ab initio potentials for both the ground and the valence electronic excited states and a 2-D approximation for vibrational motion. Due to the strong interaction between the O-Br and the Br-Br stretching ...
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 reconstructed surfaces of the sols. STM images of graphite surfaces are characterized by two ...
We report the e?ects of system size on melting of dense sodium at about 100 GPa. We have performed systematic ab initio molecular-dynamics (MD) simulations with the number of atoms at most 250 for bcc and 256 for fcc structures based on 3s-valence-electron model and 2p3s-valence-electron model. We have shown that ...
The authors have performed ab initio quantum mechanical calculations in monomeric clusters modeling the 12 different T sites of zeolite ZSM-5. By comparing the results of calculations that use minimum basis sets with those that employ valence double-[zeta] bases, the authors conclude that minimum basis sets are unreliable for ...
Electronic many-body effects alone can be responsible for the migration of a positive charge created upon ionization in molecular systems. Here, we report an ultrafast charge migration taking place after valence ionization of the molecule 4-methylphenol. The results obtained by a fully ab initio methodology show that the positive ...
Because of extensive electron correlation, the ground-state structures, infrared spectra, and chemical bonding properties of a number of tetratomic molecules which possess 23 valence electrons are anomalous. Approaches which have recently been helpful in understanding this phenomenon include ab initio calculations and spectroscopic ...
We apply a variational wave function capable of describing qualitatively and quantitatively the so-called �resonating valence bond� (RVB) in realistic materials, by improving standard ab initio calculations by means of quantum Monte Carlo methods. In this framework we clearly identify the Kekul� and Dewar contributions to the ...
We report a joint experimental and theoretical study of circular dichroism in the valence photoelectron spectra of a free chiral molecule. The circular dichroism in photoelectron spectroscopy is measured at the magic angle for various valence states of R(+) and S(-) methyl-oxirane enantiomers in the vapor phase. The maximum dichroism measured is about ...
The author has developed a fairly ab initio theory of cuprate superconductivity, based on the concept that the above-T{sub c} state is a normal Fermi liquid with strong electronic correlations of the type found in valence-fluctuation (VF) and heavy-fermion materials. The ground-state-correlation aspect is found to provide a ...
Due to recent advances in methods and computers, the accuracy of ab calculations has reached a point
NASA Technical Reports Server (NTRS)
The reaction of ethyl radicals with H atoms is of general importance in hydrocarbon combustion. The interaction of H with C2H5 is analyzed at the CAS+1+2 level employing a correlation-consistent polarized valence double zeta basis set. These ab initio cal...
Ab initio LCAO-MO-SCF calculations using several basis sets and approximate INDO-MO calculations for methyl nitrate are reported. The eigenvalues and eigenvectors are used to analyze the results of x-ray photoelectron spectroscopic studies of the molecule. Core and valence electron and satellite spectra are reported. Both the ...
Studies of higher excited states of some polyatomic molecules relevant for plasma physics and environment have been presented. Spectra of chlorofluorocarbons are discussed together with their influence on ozone layer depletion and global warming. Tetrahydrofuran molecule was studied by photoabsorption and electron energy loss spectroscopy while the states are assigned following extensive ...
Ab initio Molecular Orbital (MO) Calculations for water dimers and trimers, using a split-valence basis set supplemented with polarization functions (6-31), including electron correlation for nearest neighbor dimers via second-order Moeller Plesset theory...
Ab initio LCAO-MO-SCF calculations of the lowest singlet sigma plus states of BeNe and BeAr showed that the systems were both repulsive. Population analyses indicated that there was only a very small amount of Pi electron density transferred from the rare...
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 ...
Improved estimates of the nonrelativistic stationary nucleus correlation energies of the ground-state atomic ions with three to ten electrons and {ital Z} up to 20 are derived by combining experimental data and improved {ital ab} {ital initio} calculations. Unlike previous work in this area, we focus on the correlation contribution to individual ionization ...
We present ab initio calculations of the zero-field splitting tensors for the 100-split self-interstitial in diamond (R2) and VH2* and VO* in silicon. It is demonstrated that, especially in silicon, sampling of the Brillouin Zone (BZ) and the inclusion of all valence states in the calculation is vital.
Ab initio, embedded-cluster RHF-SCF-LCAO molecular-orbital calculations were performed on both ground and excited states of the Tl(l) center in potassium chloride. Effective core potentials and valence orbitals were employed on the thallium atom and its n...
For a series of cyclopenta-polynuclear aromatic hydrocarbons, epoxidated in the cyclopenta ring, semi-empirical AM1 calculations, and single point ab initio calculations using the 3-21g split valence basis set, have been performed for the each carbocation that might be formed by ...
EPA Science Inventory
A rigorous lower bound of 0.038 eV for the binding energy of LiH(+) has been obtained via an ab initio quantum mechanical calculation using a generalized valence-bond wavefunction with a mixed basis set of elliptic and Slater-type orbitals. The probable e...
molecules as illustrated in Figure 1. Basically, the metallo-organic Pc complex is built by two units: 1 the central metal to the ligand make the metallo-organic complex an aromatic molecule. Valence electrons-inorganic heterostructures where a tuning of the properties of the organic molecules (e.g., of NLO properties) could
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, ...
We performed configuration interaction ab initio calculations on the valence and 5s, 5p(a(1)), and 5p(e) Rydberg bands of the CH(3)Br molecule as a function of the methyl-bromide distance for frozen C(3v) geometries. The valence state potential energy curves are repulsive, the Rydberg state ones are similar to the ...
We performed configuration interaction ab initio calculations on the valence and 5s, 5pa1, and 5pe Rydberg bands of the CH3Br molecule as a function of the methyl-bromide distance for frozen C3v geometries. The valence state potential energy curves are repulsive, the Rydberg state ones are similar to the one of the ...
We present an ab initio study of the electric field gradient at Fe nuclei in the series of (FeAl)1-xTx dilute alloys with B2-type crystal structure. The ternary additions T, of concentration x ? 0.06, from the group of 3d-type transition metals (Ti, V, Cr, Mn, Co, Ni, Cu) are considered. Lattice, local valence electron (3d, 4p) and ...
The potential energy surfaces (PESs) of the two lowest excited singlet states of furan [correlating with the Rydberg (1)A(2)(3s) and valence (1)B(2)(V) states at the C(2v) ground-state molecular configuration] have been studied in some detail with regard to the photoinduced ring-opening reaction. The surfaces have been characterized in terms of their stationary points and ...
The potential energy surfaces (PESs) of the two lowest excited singlet states of furan [correlating with the Rydberg 1A2(3s) and valence 1B2(V) states at the C2v ground-state molecular configuration] have been studied in some detail with regard to the photoinduced ring-opening reaction. The surfaces have been characterized in terms of their stationary points and points of ...
Effects of increased basis-set size as well as a correlated treatment of the diagonal Born-Oppenheimer approximation are studied within the context of the high-accuracy extrapolated ab initio thermochemistry (HEAT) theoretical model chemistry. It is found that the addition of these ostensible improvements does little to increase the overall accuracy of ...
The linear and nonlinear optical (NLO) properties of the cis and trans isomers of diphenylbenzobisoxazole (PBO) and diphenylbenzobisthiazole (PBT) have been calculated by ab initio time-dependent coupled perturbed Hartree-Fock method using a split-valence basis set. The second-order NLO susceptibilities of the trans isomers are ...
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 ...
Ab initio calculations performed in this work render a near-zero but positive electron affinity of the major N(9)H tautomer of adenine. However, the electron affinity of the N(7)H tautomer, which has not been detected in the gas phase but coexists with the N(9)H tautomer in the polar solution, is predicted to be equal to 0.12 eV. ln both cases the excess ...
The structural environment of Mg in a K-bearing silicate glass of composition K2MgSi3O8 is investigated by x-ray absorption near-edge structure (XANES) spectroscopy at the Mg K-edge. XANES calculations are performed using a plane-wave electronic structure code, and a structural model obtained by classical molecular dynamics coupled to ab initio relaxation. ...
The structural environment of Mg in a K-bearing silicate glass of composition K(2)MgSi(3)O(8) is investigated by x-ray absorption near-edge structure (XANES) spectroscopy at the Mg K-edge. XANES calculations are performed using a plane-wave electronic structure code, and a structural model obtained by classical molecular dynamics coupled to ab initio ...
Bond orders and valence indexes of atoms were calculated from ab initio wave functions using the definition suggested by Mayer. Changes of these quantities were investigated under conditions occurring in chemical reactions. Calculations were performed to reveal the dependence of bond orders on bond length. The results are compared with ...
Molecular constants have been computed for the ground states {sup 2}{Pi} of {sup 17}OH and {sup 1}{Sigma} of {sup 107}AgH{sup +}. The valence-bond method and advanced computational technique were used to perform all-electron ab initio calculation of molecular electronic structures. The basic idea behind the model is to introduce the ...
As lead sulfide is an important semiconductor, it is of great interest to identify possible (meta)stable modifications, both at standard and elevated pressures. To predict such structures, global optimizations on the energy landscape of PbS were performed for several pressures, using simulated annealing followed by local optimization of the candidates found. In order to be able to take the effect ...
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 structure of Ta2O5 is experimentally studied by X-ray photoelectron ...
Ab initio calculations for the strongly exoergic Li2+F harpoon reaction are presented using density-functional theory, complete active space self-consistent field, and multireference configuration interaction methods to argue that this reaction would be an ideal candidate for investigation with ultracold molecules. The lowest six states are calculated with ...
The reaction of ethyl radicals with H atoms is of general importance in hydrocarbon combustion. The interaction of H with C{sub 2}H{sub 5} is analyzed at the CAS+1+2 level employing a correlation-consistent polarized valence double zeta basis set. These ab initio calculations show three barrierless pathways, two leading to association ...
A new global potential energy surface for the lowest triplet electronic state (a3A'') of HNO has been developed by a three-dimensional cubic spline interpolation of more than 13 000 ab initio points, which were calculated at the multireference configuration interaction level with Davidson correction using the augmented correlation-consistent polarized ...
A new global potential energy surface for the lowest triplet electronic state (a(3)A") of HNO has been developed by a three-dimensional cubic spline interpolation of more than 13,000 ab initio points, which were calculated at the multireference configuration interaction level with Davidson correction using the augmented correlation-consistent polarized ...
We have studied self-assembled bismuth (Bi) nanolines on the Bi-terminated InAs(100) surface by core-level and valence-band photoelectron spectroscopy, and ab initio first-principles calculations. A structural model for this intriguing surface is suggested based on the comparison of the measured and calculated core-level shifts. Also, ...
The crystal structures and the physical (magnetic, electrical transport and thermodynamic) properties of the ternary compounds CeRhSi2 and Ce2Rh3Si5 (orthorhombic CeNiSi2- and U2Co3Si5-type structures, respectively) were studied over wide ranges of temperature and magnetic field strength. The results revealed that both materials are valence fluctuating systems, in line 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 ...
Ab initio electronic structure methods can supplement CALPHAD in two major ways for subsequent applications to stability in complex alloys. The first one is rather immediate and concerns the direct input of ab initio energetics in CALPHAD databases. The o...
...with this part. The certificate shall be void ab initio for those vehicles causing the...issued, and the certificate may be deemed void ab initio. (C) The manufacturer...with this part. The certificate shall be void ab initio for those vehicles causing...
Code of Federal Regulations, 2010
The ground state rotational spectra of H3Si35Cl, H3Si37Cl, and D3Si35Cl have been measured from the microwave to the submillimeterwave ranges and accurate rotational parameters have been determined. For H3Si37Cl, they are in good agreement with the values obtained from the ground state combination differences. The quadratic, cubic, and semi-diagonal quartic force field has been calculated at 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 ...
An effective Hamiltonian mixed molecular orbital and valence bond (EH-MOVB) method is described to obtain an accurate potential energy surface for chemical reactions. Building upon previous results on the construction of diabatic and adiabatic potential surfaces using ab initio MOVB theory, we introduce a diabatic-coupling scaling ...
PubMed Central
... ADP023770. Title : ab-Initio Molecular Dynamics Simulations of Molten Ni-Based Superalloys. Descriptive Note : Conference paper. ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... of Molecular Modelling and Ab initio Molecular ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : New AB Initio Based Density ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Development of Ab-initio Multibody ...
... Ab initio Energies Calculated Using 3 ... of the Transition States (TS ... Descriptors : *TRANSITIONS, *MOLECULES, COMPUTATIONS, COMPARISON ...
... Abstract : Results are presented from ab initio quantum chemical calculations on the ground state potential energy surface for the open shell ...
... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... Title : An Ab Initio Study of Solid ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : An AB Initio Study of Dimethyl ...
... Accession Number : ADA523968. Title : Ab-initio Simulations of Molten Ni Alloys. Descriptive Note : Journal article (preprint). ...
... Title : Ab-Initio Molecular Dynamics Simulations of Molten Ni-Based Superalloys. Descriptive Note : Conference paper (preprint). ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab-Initio Molecular Dynamics Simulations ...
... We carried out ab-initio quantum chemical calculations on these energetic cyclic ethers and generated the electrostatic molecular potential contour ...
Ab initio quantum chemical techniques have been used to investigate weakly bund complexes of H20 and SO2. An energy gradient program was used to ...
... Accession Number : ADA351780. Title : Ab Initio and DFT Potential Energy Surfaces for Cyanuric Chloride Reactions. Descriptive Note : Final rept. ...
... Ab initio study on atomic structures and physical properties of CdSe quantum nanodots ... Figure 2. Diagram of covered nanodots. ...
... Title : Ab Initio Study on Atomic Structures and Physical Properties of CdSe Quantum Nanodots. Descriptive Note : Final rept. ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : Ab Initio Study of the Structure ...
... Rydberg I 'Flu state. Demoulin and Jungen (1974) used an ab initio quantum chemical approach, but only at the SCF level ...
... moment has been cancelled a priori for the electronic transition as a function of R(CC), using ab initio quantum chemical techniques including state ...
... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... Title : Ab Initio Study of Ultracold ...
1 AB INITIO STUDIES ON HEXAVALENT PHOSPHORUS COMPOUNDS Ashley L. Wilson* Aberdeen High School Aberdeen, Maryland 21001 ...
... Accession Number : ADA436055. Title : Ab Initio Studies on Hexavalent Phosphorus Compounds. Descriptive Note : Conference paper. ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : Ab Initio Relativistic Study of ...
... Accession Number : ADA440631. Title : Ab Initio Quantum Chemical Study of Electron Transfer in Carboranes. Descriptive Note : Journal article. ...
... Accession Number : ADA270577. Title : Ab Initio Potential Energy Surface for the H + OCS Reaction. Descriptive Note : Final rept. ...
... [2"- ARMY RESEARCH LABORATORY [C Ab Initio Potential Energy Surface for H + OCS Reactions: Extended Basis Sets ...
... Results of this study substantiate findings from an earlier quantum chemical study using a lower ... for (I) and (II) based on the earlier ab initio study. ...
... Ab initio direct trajectory simulation on hydrogen atom transfer in 7-azaindole in the electronic excited state with assist of water molecules ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab Initio Direct Trajectory Simulation on ...
... Title : Ab Initio Calculation of Vibrational Circular Dichroism Spectra Using Accurate Post-Self-Consistent-Field Force Fields: trans-2,3 ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab Initio Calculation of Intermolecular ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : AB Initio Propagator Theory of ...
Progress is reported in performing large scale valence-bond calculations of the ground and electronically excited Born-Oppenheimer eigenstates of diatomic molecules. A code suite for this purpose has been devised which combines spin-free methods in enumerating electronic configurations in terms of the standard tableau functions devised by one of us (GG - Crunch Code) with an ...
The structural and energy characteristics of the valence isomers of the nitrosocyclobutyl cation and also their rearrangement paths were studied on the basis of an analysis of the orbital interactions and quantum-mechanical calculations by the MINDO/3 and ab initio (STO-3G) methods. The eta/sup 1/ and eta/sup 4/ structures do not ...
Ab initio calculations on the ground and valence-excited states of the sulfur monofluoride radical have been performed using entirely uncontracted all-electron augmented correlation consistent polarized valence quintuple zeta basis sets and the internally contracted multireference configuration interaction with ...
In this paper we present relativistic core ab initio model potentials based on atomic Cowan-Griffin calculations, together with Wood-Boring spin-orbit operators and optimized Gaussian valence basis sets, for the lanthanide elements Ce to Lu and for the actinide elements Th to Lr. This completes the chemically relevant part of the ...
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 functions. The accuracy ...
A method is presented for expressing the occupied self-consistent-field (SCF) orbitals of a molecule exactly in terms of chemically deformed atomic minimal-basis-set orbitals that deviate as little as possible from free-atom SCF minimal-basis orbitals. The molecular orbitals referred to are the exact SCF orbitals, the free-atom orbitals referred to are the exact atomic SCF orbitals, and the ...
MCSCF-CAS and SCF ab initio calculations were carried out for the abstraction of H from CH[sub 4] by MgO and LiO molecules. Effects of the electron correlation on internuclear distances, reaction energies, and Laplacian of the charge density [del][sup 2][rho](r) of the O valence shell were studied. An excellent correlation between the ...
Ab-initio methods have been employed to investigate the electronic and elastic properties of beryllium chalcogenides (namely BeS, BeSe and BeTe). The electron momentum density, autocorrelation function and energy band gap have been computed using the linear combination of atomic orbitals method. Using the full potential linearized augmented plane-wave and projector-augmented ...
A consistent set of ab initio effective core potentials (ECP) has been generated for the main group elements from Na to Bi using the procedure originally developed by Kahn. The ECP's are derived from all-electron numerical Hartree--Fock atomic wave functions and fit to analytical representations for use in molecular calculations. For Rb to Bi the ...
Cobalt complexes with dioxolene ligands exhibit the phenomenon of valence tautomerism, i.e. a crossover from a high-spin state to a low-spin state accompanied by electron transfer, which makes them possible candidates for molecular electronic switches. In particular, experiments suggest that the transition involves the transformation of a low-spin (d^6 Co^III) complex at low ...
Double proton transfer (DPT) reaction of a 7-azaindole dimer in the first ??* electronically excited state was studied theoretically. We investigated the reaction mechanism through constructing a full dimensional empirical valence bond potential energy function (PEF) based on potential energies evaluated by ab initio molecular orbital ...
We report on the determination of a high quality ab initiu potential energy surface (PES) and dipole
