... This study involves: Ab-initio crystal orbitals and polymer orbitals; Ab-initio coupled cluster program; Ab-initio quantum chemical calculations and ...
DTIC Science & Technology
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... COMPENDIUM OF AB INITIO CALCULATIONS ...
... 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. ...
... Ab initio Energies Calculated Using 3 ... of the Transition States (TS ... Descriptors : *TRANSITIONS, *MOLECULES, COMPUTATIONS, COMPARISON ...
... We carried out ab-initio quantum chemical calculations on these energetic cyclic ethers and generated the electrostatic molecular potential contour ...
... 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 ...
... Abstract : Results are presented from ab initio quantum chemical calculations on the ground state potential energy surface for the open shell ...
Due to recent advances in methods and computers, the accuracy of ab calculations has reached a point
NASA Technical Reports Server (NTRS)
... The first approximation that is generally incorporated into the Schroedinger Theory is known as the Born Oppenheimer Approximation. ...
The number of ab initio molecular electronic calculations has increased dramatically in the last few years. Both the practitioners and other interested students of the results of the calculations have found it increasingly difficult to determine the prese...
National Technical Information Service (NTIS)
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...
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.
Energy Citations Database
Ab initio molecular orbital calculations on phosphites, protonated phosphites, and protonated phosphates reveal important stereoelectronic effects. In the phosphites, an antiperiplanar lone pair on oxygen to the phosphite lone pair raises the energy of th...
Ab initio calculations are carried out to determine ?? (true), the first-order contribution to the spin-rotation constant, ??, for the X2? ground states of ...
NASA Website
Formalisms suitable for calculating the rate of electron exchange between transition metal complexes in aqueous solution are reviewed and implemented in conjunction with ab initio quantum chemical calculations which provide crucial off-diagonal Hamiltonia...
Ab initio calculations of single and double differential cross sections for ionization by fast, charged particles within the framework of Born approximation are presented. In addition, a semiempirical method based on the asymptotic Bethe-Boron expansion i...
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...
Hensley, J.M., S. Green, and G.W. Flynn, 1991: A simple ab initio calculation for energy transfer in collisions of hot hydrogen atoms with carbon dioxide. ...
In the second phase, a ultrafast semi-empirical ab initio method is ... High level quantum chemical calculations are then performed to further narrow down ...
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 ...
NASA Astrophysics Data System (ADS)
... goals of this program have been to develop new, more effective methods for performing accurate ab initio electronic structure calculations and to ...
Metal atom clusters are studied based on the application of ab initio quantum mechanical approaches.
... Molecular Orbital Studies on Nucleoside Antibodies VIII, Ab Initio Calculation of Cubic Force Constants in Formamide Monomer, Formamide Dimer ...
... Concomitantly, we calculated the fundamental interactions of fluorine atoms with silicon using ab initio quantum mechanics, in order to understand ...
... agencies for Research Development Test and Evaluation ... Potentials of Mixed Systems: Testing the Lorentz ... Mixing Rules with Ab Initio Calculations. ...
... (U) DEVELOPMENT OF EFFECTIVE QUANTUM CHEMICAL METHOD FOR ... array of semiempirical approaches and ab initio calculations followed ...
... Corporate Author : NATIONAL STANDARD REFERENCE DATA SYSTEM. ... observable properties including the total energy, dissociation energy ...
We have carried out extensive high quality ab initio electronic structure calculations of the ground
We report on the determination of a high quality ab initiu potential energy surface (PES) and dipole
The nuclear magnetic resonance chemical shift is one of the most powerful properties available for structure determination at the molecular level. A review of advances made in the ab initio calculation of chemical shielding during the past five years is presented. Specifically, progress in the areas including the effects of an unpaired ...
The temperature-dependent mass diffusion coefficient is computed using transition state theory. Ab initio supercell phonon calculations of the entire system provide the attempt frequency, the activation enthalpy, and the activation entropy as a function o...
The predissociation line broadening in the Schumann-Runge bands of O2 is explained by an ab initio calculation of the pertinent repulsive potential energy curves and spin-orbit matrix elements. The ab initio results provide an overall qualitative picture ...
The detailed molecular structure of methyl phosphonate, the simplest phosphorus ester, was determined by ab initio quantum-chemical calculations in a variety of basis sets. Computed properties include the optimized structure, dipole moment, number and rel...
the parameters for a polarizable force field from ab initio quantum-chemical calculations, and a rigorous method initio quantum- chemical calculations have become an increasingly impor- tant source of fitting dataParametrizing a polarizable force field from ab initio data. ...
E-print Network
SnO2: BULK AND SURFACE SIMULATIONS BY AN AB INITIO NUMERICAL LOCAL ORBITALS METHOD A.V. POSTNIKOVa structure of ideal bulk SnO2 is well studied by ab initio calculations (Peltzer y Blanc�a, Svane study of several SnO2 surfaces, com- paring their energies of formation, and started to look
This study involves: Ab-initio crystal orbitals and polymer orbitals; Ab-initio coupled cluster program; Ab-initio quantum chemical calculations and electrostatic molecular potential contour maps for cationic polymerization; Prediction of crystal density;...
with molecular dynamic simulations in combination with high level correlated ab initio quantum chemical the existing minima in the PES. 2. Ab initio quantum-chemical calculations. The lowest energy minima (within surface analysis by metadynamics. Gibbs energies and populations obtained from ...
-body mul- tipartitioning perturbation theory MPPT ,9 which seems to be more adequate for the description. Ab initio finite-field MPPT transition dipole moment functions obtained with the two atomic basis ( em PSZ ) and KN--Ref. 7 ( em KN ); b ab initio calculated in the present work FF-MPPT, ...
NMR chemical shifts for an L-alanine molecular crystal are calculated using ab initio plane wave density functional theory. Dynamical effects including anharmonicity may be included by averaging chemical shifts over an ensemble of structural configurations generated using molecular dynamics (MD). The time scales required mean that ...
PubMed
Ab initio calculations on polyatomic molecules and solids have progressed to the point that complexes containing any atom in the periodic table can be treated. If a meaningful comparison with experiment is desired, the relativistic terms in the Hamiltonia...
... 3. Ab initio calculations on ammonia, formamide, pyrrole and pyridine. ... The results given in Appendix II for formamide (HCONH2) are typical of the ...
... Detailed analyses, including 6-31G' and MP2/6-31G* ab initio calculations, were performed for ... formed comparative quantum chemical calculations ...
coupling between two QDs. We first parted the Icosahedral QDs by vaccum and calculated the Total Density
The third-order susceptibility of H2 has been calculated under coherent anti-Stokes Raman-scattering
The generalized two-dimensional Peierls-Nabarro (PN) model7 for studying interfaces is developed further, where an exact generalized stacking fault energy ?-surface obtained from ab initio calculations acts as an input function for the generalized PN model. Using the multiscale modeling techniques, which combines elastic theory with ...
Through the use of a molecular pseudopotential method, we determine the a approximate magnitudes of errors that result when electron affinity determinations of polar negative ions are made through ab initio calculations in which the use of a given basis set yields inappropriate values for permanent and induced dipole moments of the ...
... nanotubes. We performed ab-initio density functional calculations and studied the optical properties of aligned SWNTs that form carbon nanotube ...
Ab initio calculations have been carried out on the first- and second-row transition-metal mono- and
... goals of this program have been to develop new, more effective methods for perform in accurate ab initio electronic structure calculations and to ...
Ab initio molecular orbital theory has been used to determine the equilibrium geometries, rotational
Ab Initio calculations for defects and impurities in elemental and compound semiconductors Characterization of defects and impurities in compound semiconductors Modeling of...
Science.gov Websites
The results of an ab initio calculation of the potential energy surface governing atomic hydrogen recombination in the presence of helium atoms are presented. (auth)
... cation. Enthalpies of formation were calculated for gas phase N3, N3(-), N5+, and N3 from ab initio molecular orbital theory. ...
... softening of Al-based fcc alloys using ab initio Korringa-Kohn-Rostoker augmented-spherical-wave electronic structure calculations is discussed. ...
Ab initio calculations on the ground states of the alkali dimers, Na2, K2, and Rb2, and their anions
... previous grant period have been to develop new, more effective methods for performing accurate ab initio electronic structure calculations and to ...
Spectroscopic constants and dissociation energies for the ground states of N2, O2, and F2 determined
For some simple, but nontrivial molecular systems, the interaction potentials are now well determined from ab initio electronic structure calculations ...
... The results are in perfect qualitative and good quantitative agreement with existing experimental VCD spectra except in the CH stretching region of ...
... Abstract : Electronic structure calculations using theoretical methods based on the linked-diagram theorem are reported for a series of dissociation ...
Mar 1, 2011 ... Conformational Characteristics of Poly(tetrafluoroethylene) (PTFE) Based Upon Ab Initio Electronic Structure Calculations on Model Molecules ...
