The energy difference between the linear 2 sigma(sup +, sub u) and cyclic 2B(sub 2) structures of C3(+) has been investigated using large (5s3p2d1f) basis sets and multireference electron correlation treatments, including complete active space self consis...
National Technical Information Service (NTIS)
The electric dipole transition moment has been cancelled a priori for the electronic transition as a function of R(C-C), using ab initio quantum chemical techniques including state averaged, complete active space MCSCF and multireference CI. The transitio...
Structural and energetic properties of small, deceptively simple anionic clusters of lithium, Li(n)(-), n = 3-7, were determined using a combination of anion photoelectron spectroscopy and ab initio calculations. The most stable isomers of each of these anions, the ones most likely to contribute to the photoelectron spectra, were found using the gradient ...
PubMed
Structural and energetic properties of small, deceptively simple anionic clusters of lithium, Lin-, n = 3-7, were determined using a combination of anion photoelectron spectroscopy and ab initio calculations. The most stable isomers of each of these anions, the ones most likely to contribute to the photoelectron spectra, were found using the gradient ...
NASA Astrophysics Data System (ADS)
We report a highly correlated multireference configuration interaction calculation of the near-equilibrium potential energy surface of ozone using a large correlation consistent basis set. Three-dimensional analytical expressions are obtained for the potential energy and dipole moment functions using least-squares fits to ab initio ...
Energy Citations Database
Cross sections for the radiative association of Si+, P+, and S+ with atomic hydrogen to form the diatomic molecular ions SiH+, PH+, and SH+, respectively, are presented. The results are obtained using fully quantum-mechanical techniques and utilize ab initio molecular data calculated with the multireference single- and ...
Features of the potential energy surface pertinent to the thermal decomposition mechanism of methylenenitramine (CH(sub 2)NNO(sub 2)) are investigated. At issue are the activation energies both for concerted molecular dissociation leading to HCN and HONO ...
The recently developed reduced multireference coupled-cluster method with singles and doubles (RMR CCSD), which is perturbatively corrected for triples [RMR CCSD(T)], is employed to compute binding energies of nine transition metal ions with CH2. Unlike analogous compounds involving main-group elements, the MCH2+ (M=Sc to Cu) transition metal complexes often exhibit a ...
Ab initio calculations at the multiconfiguration self-consistent field level followed by a multireference configuration interaction were carried out along the two possible collinear approaches of the [LiHHe]+ system, while a three-dimensional calculation of the structures of that complex with LiH+ kept at its equilibrium geometry was ...
The potential energy surface of the ground state of the He-MnH(X (7)Sigma(+)) van der Waals complex is presented. Within the supermolecular approach of intermolecular energy calculations, a grid of ab initio points was computed at the multireference configuration interaction level using the aug-cc-pVQZ basis set for helium and hydrogen ...
A theoretical treatment of charge-transfer processes induced by collision of phosphorus P{sup 3+}(3s{sup 2}){sup 1}S ions on atomic hydrogen and helium has been carried out using ab initio potential-energy curves and couplings at the multireference configuration interaction level of theory. The cross sections calculated by means of ...
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 ...
Several excited singlet electronic states of purine nucleobases and related derivatives have been calculated using high-level multireference perturbation theory methods. Purine derivatives with one or two amino or carbonyl groups substituted at positions C(2) and/or C(6) of the purine ring have been included in the study. The effect of the substituents on excited-state ...
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 ...
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 ...
An investigation into spin structures of poly(m-phenylenecarbene), a prototype of magnetic organic molecules, is presented using the ab initio density matrix renormalization group method. It is revealed by achieving large-scale multireference calculations that the energy differences between high-spin and low-spin states (spin-gaps) of ...
The mechanistic photodissociations of several series of aliphatic and aryl halides have been theoretically investigated using multireference ab initio calculations. The photodissociations of halomethanes were also investigated by spin-orbit ab initio calculations. Based on the calculated ...
The magnetic exchange interaction behavior and energy spectrum of low-lying spin states are investigated by using ab initio multireference configuration-interaction method for the representative binuclear transition-metal complexes [(NH(3))(5)Cr(mu-OH)Cr(NH(3))(5)](5+) and [Cl(3)FeOFeCl(3)](2-). Our calculations for the nonmodeling ...
The magnetic exchange interaction behavior and energy spectrum of low-lying spin states are investigated by using ab initio multireference configuration-interaction method for the representative binuclear transition-metal complexes [(NH3)5Cr(?-OH)Cr(NH3)5]5+ and [Cl3FeOFeCl3]2-. Our calculations for the nonmodeling real title complexes ...
... This study involves: Ab-initio crystal orbitals and polymer orbitals; Ab-initio coupled cluster program; Ab-initio quantum chemical calculations and ...
DTIC Science & Technology
The multiconfigurational CASSCF/CASPT2 approach, along with various functionals of density functional theory, is applied to selected iron(II)-nitrosyl ({FeNO}(7)) complexes, both with heme and nonheme groups. The energetics of the lowest doublet and quartet spin states at the correlated ab initio (CASPT2) level is presented for the first time. Comparison ...
In common with many of the computational sciences, ab initio chemistry faces computational constraints to which a partial solution is offered by the prospect of highly parallel computers. Ab initio codes are large and complex (O(10{sup 5}) lines of FORTRAN), representing a significant investment of communal effort. ...
In this paper we report a theoretical study of the static dipole polarizability of two one-dimensional structures: (a) linear carbon chains Cn (n=2-10) and (b) ladderlike planar boron chains Bn (n=4-14). The polarizabilities of these chains are calculated both at the Hartree-Fock and the correlated levels by applying accurate ab initio quantum-chemical ...
Ab initio global adiabatic and quasidiabatic potential energy surfaces of lowest four electronic (1-4 3A'') states of the H++O2 system have been computed in the Jacobi coordinates (R,r,?) using Dunning's cc-pVTZ basis set at the internally contracted multireference (single and double) configuration interaction level of accuracy, which ...
Ab initio global adiabatic and quasidiabatic potential energy surfaces of lowest four electronic (1-4? (3)A(")) states of the H(+)+O(2) system have been computed in the Jacobi coordinates (R,r,?) using Dunning's cc-pVTZ basis set at the internally contracted multireference (single and double) configuration interaction level of ...
A highly accurate, global dipole moment surface (DMS) is calculated for the water molecule using ab initio quantum chemistry methods. The new surface is named LTP2011 and is based on all-electron, internally contracted multireference configuration interaction, including size-extensivity corrections in the aug-cc-pCV6Z basis set. ...
... 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,. ...
In a previous publication (1997. P. Jensen, J. Mol. Spectrosc. 181, 207-214), rotation-vibration energy levels for the electronic ground state X3B1 of the amidogen ion, NH2+, were predicted using the MORBID Hamiltonian and computer program with an ab initio potential energy surface. In the present paper we calculate a new ab ...
... 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
NASA Technical Reports Server (NTRS)
We analyze the adiabatic potential-energy surfaces relevant for neutralization of singly charged ions in slow vertical incidence onto a lithium fluoride surface. The surface is represented by a cluster of varying size augmented by point charges of alternating sign in order to include the proper Madelung potential of the ionic crystal. Our calculation proceeds on the multiconfiguration ...
Fixed-node diffusion quantum Monte Carlo (FN-DMC) calculations are performed to obtain the most accurate dissociation barrier and heat of formation with respect to dissociation into molecular oxygen for the chemically bound tetraoxygen molecule. Multireference trial wave functions were used and built from truncated CASSCF(16,12) through a weight-consistent scheme allowing to ...
We have devised a local ab initio density matrix renormalization group algorithm to describe multireference correlations in large systems. For long molecules that are extended in one of their spatial dimensions, we can obtain an exact characterization of correlation, in the given basis, with a cost that scales only quadratically with ...
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 single and double ...
Theoretical investigation of low-lying electronic states and B3?-u-X3?-g transition properties of selenium dimer using size-extensivity singly and doubly excitation multireference configuration interaction theory with nonrelativistic all-electron basis set and relativistic effective core potential plus its split valence basis set is presented in this paper. The spectroscopic ...
The formation of spiropentane, by addition of singlet (1A1) methylene to methylenecyclopropane, and the unimolecular reactions of spiropentane have all been studied computationally. Benchmark calculations on two key biradicals were conducted by the multireference Mukherjee's coupled-cluster (MkCC) method. Various single-reference coupled-cluster methods and ...
The doublet and quartet potential energy surfaces for the Ti{sup +}+C{sub 2}H{sub 6}{yields}TiC{sub 2}H{sub 4}{sup +}+H{sub 2} and Ti{sup +}+C{sub 2}H{sub 6}{yields}TiCH{sub 2}{sup +}+CH{sub 4} reactions are studied using density functional theory (DFT) with the B3LYP functional and ab initio coupled cluster CCSD(T) methods with high quality basis sets. ...
A fully ab initio scheme based on quantum chemical wavefunction methods is used to investigate the correlated multiorbital electronic structure of a 3d-metal compound, LaCoO3. The strong short-range electron correlations, involving both Co and O orbitals, are treated by multireference techniques. The use of effective parameters such as ...
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 of the ...
In this work, we report on our full results of the spectroscopic analysis of the quasi-linear S2 state of the prototypical halocarbene, CHF, and its deuterated isotopomer CDF using optical-optical double resonance spectroscopy through the S1 state. A total of 51 S2 state vibrational levels with angular momenta in the range l = 0-3 were observed for CHF, and 76 levels for CDF. Progressions ...
A new implementation of nonadiabatic excited-state dynamics using hybrid methods is presented. The current approach is aimed at the simulation of photoexcited molecules in solution. The chromophore is treated at the ab initio level, and its interaction with the solvent is approximated by point charges within the electrostatic embedding approach and by a ...
Electronic structure theory faces many computational challenges in transition metal chemistry. Usually, density functional theory is the method of choice for theoretical studies on transition metal complexes and clusters mostly because it is the only feasible one, although its results are not systematically improvable. By contrast, multireference ab ...
New ab initio potential energy surfaces for the ground (X?1A') and excited (�1A?) electronic states of HSiCl were obtained by using the single and double excitation coupled-cluster theory with a noniterative perturbation treatment of triple excitations and the multi-reference configuration interaction with Davidson correction, ...
A new global potential energy surface is reported for the ground state (4A'') of the reaction H(2S) + NH(X3?-) --> N(4S) + H2 from a set of accurate ab initio data, which were computed using the multi-reference configuration interaction with a basis set of aug-cc-pV5Z. The many-body expansion and neural network methods have been ...
A new global potential energy surface is reported for the ground state ((4)A(")) of the reaction H((2)S) + NH(X(3)?(-)) ? N((4)S) + H(2) from a set of accurate ab initio data, which were computed using the multi-reference configuration interaction with a basis set of aug-cc-pV5Z. The many-body expansion and neural network methods have ...
This commentary focuses on the conceptual interpretation of the bonding of O(2) and NO to heme in oxyheme and nitrosylheme complexes, using high-level ab initio complete active space self-consistent field (CASSCF)/molecular mechanical (MM), gas-phase CASSCF, and CASSCF followed by second-order perturbation theory (CASPT2) calculations as well as density ...
Accurate intermolecular potentials for the lowest three multiplet states of O2-O2 dimer have been produced on the basis of ab initio calculations. The quintet potential was taken from previous highly correlated CCSD(T) calculations. In this work, we perform MRCI calculations, with large basis sets including bond functions, of the singlet and triplet ...
The authors report extensive high-level ab initio studies of the first excited (A~ 2A') state of HO2. A global potential energy surface (PES) was developed by spline-fitting 17 000 ab initio points at the internal contracted multireference configuration interaction (icMRCI) level with the AVQZ ...
The global potential energy surfaces for both the ground (X~1A') and excited (A~1A'') electronic states of the HNO molecule have been constructed by three-dimensional cubic spline interpolation of more than 17 000 ab initio points, which have been calculated at the internal contracted multi-reference configuration interaction level ...
The global potential energy surfaces for both the ground (X?(1)A(')) and excited (A?(1)A('')) electronic states of the HNO molecule have been constructed by three-dimensional cubic spline interpolation of more than 17?000 ab initio points, which have been calculated at the internal contracted multi-reference configuration interaction ...
We present a new potential energy surface (PES) for the ground state (12A') of the chemical reaction Ne+H2+ from a set of accurate ab initio data, which were computed using highly correlated complete active space self-consistent field and multireference configuration interaction wave functions with a basis set of aug-cc-pV5Z. The ...
We present a new potential energy surface (PES) for the ground state (1(2)A(')) of the chemical reaction Ne+H(2) (+) from a set of accurate ab initio data, which were computed using highly correlated complete active space self-consistent field and multireference configuration interaction wave functions with a basis set of aug-cc-pV5Z. ...
A simple but accurate and computationally efficient method for routine ab initio calculations of molecular Rydberg states is described. The method, which can be applied to Rydberg states associated with a nondegenerate ion core, consists in the self-consistent solution of an effective one-electron problem. First, the restricted Hartree-Fock problem of the ...
A three-dimensional global potential energy surface for the ground electronic state of MgH(2) is constructed from more than 3000 ab initio points calculated using the internally contracted multireference configuration interaction method with the Davidson correction at the complete basis set limit. Low-lying vibrational energy levels of ...
A global potential-energy surface for the first excited electronic state of NH(2)(A(2)A(')) has been constructed by three-dimensional cubic spline interpolation of more than 20,000 ab initio points, which were calculated at the multireference configuration-interaction level with the Davidson correction using the augmented ...
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 methods, and carrying ...
The widely accepted assumption that the development of more efficient single molecule magnets must involve ever higher total spin values has so far driven synthetic efforts towards molecular clusters of increasing nuclearity. In the present paper it is suggested that it might be worthwhile to reconsider this approach. There is evidence from theory and experiment to suggest that the race for ...
Accurate calculation of hyperfine structure of (d+s)[sup n] states involves dealing with both relativistic and correlation effects in a multi-reference framework (all (d+s)[sup n] states of fixed n,J treated at once). The algorithms were improved (BCB and REDUCE methods) and applied to the hfs of Zr II for (d+s)[sup 3] states. The fs intervals were determined to within 0.075 ...
For the van der Waals C(2)(X (1)Sigma(g)(+))-H(2) molecular system, we generated a new ab initio potential energy surface (PES). We mapped this PES at the multireference internally contracted configuration-interaction method including the Davidson correction together with a large diffuse basis set. Then, we incorporated our PES into ...
Using the multireference configuration interaction method with a Davidson correction and a large orbital basis set (aug-cc-pVQZ), we obtain an energy grid that includes 32 038 points for the construction of a new analytical potential energy surface (APES) for the Ne + H(2)(+) ? NeH(+) + H reaction. The APES is represented as a many-body expansion containing 142 parameters, ...
It is found that HRnCCH and HRnOH are metastable, chemically bound compounds of radon. These molecules are studied by multi-reference ab initio methods. Equilibrium geometry, NBO partial charges and bond orders, harmonic frequencies, are calculated. Intrinsic life-times are obtained by calculating the dissociation barriers and related ...
The solution of the first principle equations of quantum mechanics provides an increasingly accurate and predictive approach for solving problems involving atoms and small molecules. A general introduction to the methods used for the ab initio calculation of rotational-vibrational spectra of small molecules is presented, with a strong focus on triatomic ...
The potassium trimer is investigated in its lowest electronic doublet states, employing several high-level ab initio methods (coupled cluster with single, double, and noniterative triple excitations, multiconfiguration self-consistent field, and multireference Rayleigh-Schr�dinger perturbation theory of second order). One-dimensional ...
The following final report summarizes four years of research for ONR on the topic of 'Many-Body Quantum Mechanical Studies of Molecular Clusters.' There are two primary aspects of this effort, a methodological part focusing on new first principle (i.e. ab initio) multi-reference coupled-cluster methods for obtaining improved solutions ...
We report the development of a general order relativistic coupled-cluster (CC) code. Our implementation is based on Kramers-paired molecular spinors, utilizes double group symmetry, and is applicable with the full Dirac-Coulomb and several approximate relativistic Hamiltonians. The available methods include iterative and perturbative single-reference CC approaches with arbitrary excitations as ...
The photophysical and photochemical behavior of nucleobases is very important because of their biological role as the building blocks in DNA and RNA. Great progress has been made in understanding the excited-state properties of single bases. In order to understand the photophysical properties of nucleobases in complex environments we have investigated their excited states (a) in aqueous solutions ...
In recent years the charge transfer involving Si4+ and H at low energies has drawn considerable attention both theoretically and experimentally due to its importance not only in astronomical environments but also in modern semiconductor industries. Accurate information regarding its molecular structures and interactions are essential to understand the low energy collision dynamics. ...
In this commentary the challenges faced in the application of wavefunction-based ab initio methods to (open-shell) transition metal complexes of (bio)inorganic interest are briefly touched on. Both single-reference and multireference methods are covered. It is stressed that the generation and nature of the reference wavefunction is a ...
Atmospheric ozone is formed by the O + O(2) exchange reaction followed by collisional stabilization of the O(3) (?) intermediate. The dynamics of the O + O(2) reaction and to a lesser extent the O(3) stabilization depend sensitively on the underlying potential energy surface, particularly in the asymptotic region. Highly accurate Davidson corrected multi-state multi-reference ...
Atmospheric ozone is formed by the O + O2 exchange reaction followed by collisional stabilization of the O3* intermediate. The dynamics of the O + O2 reaction and to a lesser extent the O3 stabilization depend sensitively on the underlying potential energy surface, particularly in the asymptotic region. Highly accurate Davidson corrected multi-state multi-reference ...
Quantum Monte Carlo methods are used to investigate the binding of a positron to the alkali-metal hydrides, XH (X = Na and K). We obtain positron affinities for the NaH and KH molecules of 1.422(10) eV and 2.051(39) eV, respectively. These are considerably larger than the previous results of 1.035 eV and 1.273 eV obtained from multireference single- and double-excitation ...
The vibronic structure of the S0-->S1 and the S0-->S2 electronic transitions of acetylene is studied theoretically based on an ab initio quantum-dynamical approach. The underlying potential-energy surfaces and transition dipole moment functions are obtained from high-level multireference calculations, including the Davidson ...
... AB-INITIO SIMULATION OF a/2110> ... 4. TITLE AND SUBTITLE AB-INITIO SIMULATION OF a/2110> SCREW DISLOCATIONS γ-TiAl 5c. ...
... ADP012740 TITLE: Ab Initio Study on Spin Polarization of III-V Compound Tips ... Ab initio study on spin polarization of III-V compound tips ...
Ab initio electronic structure methods can supplement CALPHAD in two major ways for subsequent applications to stability in complex alloys. The first one is rather immediate and concerns the direct input of ab initio energetics in CALPHAD databases. The o...
...with this part. The certificate shall be void ab initio for those vehicles causing the...issued, and the certificate may be deemed void ab initio. (C) The manufacturer...with this part. The certificate shall be void ab initio for those vehicles causing...
Code of Federal Regulations, 2010
We present a generalization to our previously developed quantum wavepacket ab initio molecular dynamics (QWAIMD) method by using multiple diabatic electronic reduced single particle density matrices, propagated within an extended Lagrangian paradigm. The Slater determinantal wavefunctions associated with the density matrices utilized may be orthogonal or ...
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 electron correlation. A parallel ab ...
... ADP023770. Title : ab-Initio Molecular Dynamics Simulations of Molten Ni-Based Superalloys. Descriptive Note : Conference paper. ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... of Molecular Modelling and Ab initio Molecular ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : New AB Initio Based Density ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Development of Ab-initio Multibody ...
... Ab initio Energies Calculated Using 3 ... of the Transition States (TS ... Descriptors : *TRANSITIONS, *MOLECULES, COMPUTATIONS, COMPARISON ...
... Abstract : Results are presented from ab initio quantum chemical calculations on the ground state potential energy surface for the open shell ...
... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... Title : An Ab Initio Study of Solid ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : An AB Initio Study of Dimethyl ...
... Accession Number : ADA523968. Title : Ab-initio Simulations of Molten Ni Alloys. Descriptive Note : Journal article (preprint). ...
... Title : Ab-Initio Molecular Dynamics Simulations of Molten Ni-Based Superalloys. Descriptive Note : Conference paper (preprint). ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab-Initio Molecular Dynamics Simulations ...
... We carried out ab-initio quantum chemical calculations on these energetic cyclic ethers and generated the electrostatic molecular potential contour ...
Ab initio quantum chemical techniques have been used to investigate weakly bund complexes of H20 and SO2. An energy gradient program was used to ...
NASA Website
... Accession Number : ADA351780. Title : Ab Initio and DFT Potential Energy Surfaces for Cyanuric Chloride Reactions. Descriptive Note : Final rept. ...
... Ab initio study on atomic structures and physical properties of CdSe quantum nanodots ... Figure 2. Diagram of covered nanodots. ...
... Title : Ab Initio Study on Atomic Structures and Physical Properties of CdSe Quantum Nanodots. Descriptive Note : Final rept. ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : Ab Initio Study of the Structure ...
... Rydberg I 'Flu state. Demoulin and Jungen (1974) used an ab initio quantum chemical approach, but only at the SCF level ...
... moment has been cancelled a priori for the electronic transition as a function of R(CC), using ab initio quantum chemical techniques including state ...
... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... Title : Ab Initio Study of Ultracold ...
1 AB INITIO STUDIES ON HEXAVALENT PHOSPHORUS COMPOUNDS Ashley L. Wilson* Aberdeen High School Aberdeen, Maryland 21001 ...
... Accession Number : ADA436055. Title : Ab Initio Studies on Hexavalent Phosphorus Compounds. Descriptive Note : Conference paper. ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : Ab Initio Relativistic Study of ...
... Accession Number : ADA440631. Title : Ab Initio Quantum Chemical Study of Electron Transfer in Carboranes. Descriptive Note : Journal article. ...
... Accession Number : ADA270577. Title : Ab Initio Potential Energy Surface for the H + OCS Reaction. Descriptive Note : Final rept. ...
... [2"- ARMY RESEARCH LABORATORY [C Ab Initio Potential Energy Surface for H + OCS Reactions: Extended Basis Sets ...
... Results of this study substantiate findings from an earlier quantum chemical study using a lower ... for (I) and (II) based on the earlier ab initio study. ...
... Ab initio direct trajectory simulation on hydrogen atom transfer in 7-azaindole in the electronic excited state with assist of water molecules ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab Initio Direct Trajectory Simulation on ...
... Title : Ab Initio Calculation of Vibrational Circular Dichroism Spectra Using Accurate Post-Self-Consistent-Field Force Fields: trans-2,3 ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab Initio Calculation of Intermolecular ...
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : AB Initio Propagator Theory of ...
Proton-transfer reactions are important in chemical and biological processes, including photosynthesis and vision. The multiple reference double-excitation configuration interaction method (MRD-CI) and the coupled cluster method (CCM) were applied for the studies of the ground-state and low-lying excited states for the proton-transfer system (H{sub 3}N---H---OH{sub 2}){sup +}. The geometry ...
We report on the determination of a high quality ab initiu potential energy surface (PES) and dipole
A new band system of C2, e 3?g-c 3?u+ was studied by ab initio quantum chemical and experimental methods. The calculations were carried out at the multireference configuration interaction level of theory with Davidson's correction using aug-cc-pV6Z basis set and include core and core-valence correlation as well as relativistic ...
Two new global ab initio potential energy surfaces (called BW1 and BW2) for the ClH2 reactive system are presented. These are based on internally contracted multireference configuration interaction calculations using a very large basis set, performed at 1200 geometries. Accurate analytical fits have been generated using the functional ...
The structural, electronic, vibrational, optical, magnetic, and aromatic characteristics of Sin, Sin1-, Sin2-, and Sin1+, clusters have been calculated very accurately with a variety of high level ab initio techniques. These calculations have been performed with the aim to clarify existing ambiguities in the literature and to bring up the fluxional and ...
High level ab initio potential energy functions have been constructed for LiH in order to predict vibrational levels up to dissociation. After careful tests of the parameters of the calculation, the final adiabatic potential energy function has been composed from: (a) an ab initio nonrelativistic potential obtained ...
The entrance channel of the Si+O2-->SiO+O reaction has been investigated for collinear and perpendicular approach of the silicon atom to the O2 molecule by ab initio electronic structure calculations using the multireference configuration interaction (MRCI) method and Davidson correction (MRCI+Q). Results show that the reaction can ...
