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1
Formalisms for Electron Exchange Kinetics in Aqueous Solution, and the Role of Ab Initio Techniques in Their Implementation.
1980-01-01

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...

National Technical Information Service (NTIS)

2
Reactive Resonances in N+N2 Exchange Reaction.
2003-01-01

Rich reactive resonances are found in a 3D quantum dynamics study of the N + N2 exchange reaction using a recently developed ab initio potential energy surface. This surface is characterized by a feature in the interaction region called Lake Eyring , that...

National Technical Information Service (NTIS)

3
Quantum Chemical Investigations of the Mechanism of ...
1983-10-28

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

DTIC Science & Technology

4
The intrinsic reaction coordinate. An ab initio calculation for HNC-->HCN and H-+CH4-->CH4+H-
1977-03-01

A practical method of calculating the intrinsic reaction coordinate starting at a saddle point is proposed. The method has been used in combination with the analytical evaluation of the energy gradient for the calculation of the reaction coordinate on an ab initio potential energy surface. The reaction coordinates are obtained for the HNC to HCN ...

NASA Astrophysics Data System (ADS)

5
Electronic Structure of SiH5(-) and Model Studies of Inter- and Intramolecular Exchange in Pentacoordinate Silicon Species. An ab Initio Investigation.
1972-01-01

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...

National Technical Information Service (NTIS)

6
Ab initio Potential-Energy Surfaces and Electron-Spin-Exchange Cross Sections for H-O2 Interactions.
1996-01-01

Accurate quartet- and doublet-state potential-energy surfaces for the interaction of a hydrogen atom and an oxygen molecule in their ground states have been determined from an ab initio calculation using large-basis sets and the internally contracted mult...

National Technical Information Service (NTIS)

7
Chalcopyrite Magnetic Semiconductors: An Ab-Initio Study of ...
2001-04-01

... Title : Chalcopyrite Magnetic Semiconductors: An Ab-Initio Study of Their Structural, Electronic and Magnetic Properties. ...

DTIC Science & Technology

8
COMPENDIUM OF AB INITIO CALCULATIONS OF ...
1967-12-01

... from federally funded research, testing and training ... for Research Development Test and Evaluation ... COMPENDIUM OF AB INITIO CALCULATIONS ...

DTIC Science & Technology

9
An Ab Initio Study of the Geometry and Rotational Barrier of 4 ...
1990-03-16

... Accession Number : ADA219907. Title : An Ab Initio Study of the Geometry and Rotational Barrier of 4- Phenylimidazole. ...

DTIC Science & Technology

10
Ab Initio Calculations of the Magnetic Anisotropy.
1987-05-01

... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... Title : Ab Initio Calculations of the ...

DTIC Science & Technology

11
Ab Initio Calculation of Vibrational Absorption and Circular ...
1995-02-01

... Title : Ab Initio Calculation of Vibrational Absorption and Circular Dichroism Spectra Using Density Functional Force Fields. ...

DTIC Science & Technology

12
AB Initio Quantum Chemical Investigations of Solubilities in ...
1992-11-17

... Title : AB Initio Quantum Chemical Investigations of Solubilities in Supercritical Solutions. Descriptive Note : Conference Paper,. ...

DTIC Science & Technology

13
Ab initio and Gordon--Kim intermolecular potentials for two nitrogen molecules
1980-07-01

Both ab initio MO--LCAO--SCF and the electron-gas (or Gordon--Kim) methods have been used to compute the intermolecular potential (Phi) of N/sub 2/ molecules for seven different N/sub 2/--N/sub 2/ orientations. The ab initio calculations were carried out using a (4s3p) contracted Gaussian basis set with and without ...

Energy Citations Database

14
Prediction method abstracts
1994-12-31

This conference was held December 4--8, 1994 in Asilomar, California. The purpose of this meeting was to provide a forum for exchange of state-of-the-art information concerning the prediction of protein structure. Attention if focused on the following: comparative modeling; sequence to fold assignment; and ab initio folding.

DOE Information Bridge

15
Towards efficient ab initio calculations of electron scattering by polyatomic molecules: II. Efficient evaluation of exchange integrals
2010-09-01

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 ...

NASA Astrophysics Data System (ADS)

16
Direct calculation of equilibrium constants for isotopic exchange reactions by ab initio molecular orbital theory
1980-04-23

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 ...

Energy Citations Database

17
Accuracy of recent potential energy surfaces for the He-N2 interaction. I. Virial and bulk transport coefficients
2007-08-01

A new exchange-Coulomb semiempirical model potential energy surface for the He-N2 interaction has been developed. Together with two recent high-level ab initio potential energy surfaces, it has been tested for the reliability of its predictions of second-virial coefficients and bulk transport phenomena in binary mixtures of He and N2. ...

NASA Astrophysics Data System (ADS)

18
AB Initio Study of the Electronic Magnetic Circular Dichroism ...
1991-01-15

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

DTIC Science & Technology

19
Thermal rates of hydrogen exchange of methane with zeolite: A direct ab initio dynamics study on the importance of quantum tunneling effects
1997-04-10

We present a direct ab initio dynamics study on the kinetics of the hydrogen exchange of methane with a zeolite model. Dynamical calculations are based on the canonical variational transition state theory plus multidimensional semiclassical tunneling corrections. The reaction path information needed for rate calculations was computed ...

Energy Citations Database

20
Molecular Spectroscopy by Ab Initio Methods
1994-01-01

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

NASA Technical Reports Server (NTRS)

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21
Calculating geochemical reaction pathways--exploration of the inner-sphere water exchange mechanism in Al(H2O)6(3+)(aq) + nH2O with ab Initio calculations and molecular dynamics.
2008-03-27

We have simulated exchange of inner-sphere and bulk water molecules for different sizes of Al3+(aq) clusters, Al(H2O)63+ + nH2O for n = 0, 1, 6, or 12, with ab initio and molecular dynamics simulations, in order to understand how robust the ab initio method is for identifying hydrolytic ...

PubMed

22
Comparing ab initio density-functional and wave function theories: The impact of correlation on the electronic density and the role of the correlation potential.
2011-09-21

The framework of ab initio density-functional theory (DFT) has been introduced as a way to provide a seamless connection between the Kohn-Sham (KS) formulation of DFT and wave-function based ab initio approaches [R. J. Bartlett, I. Grabowski, S. Hirata, and S. Ivanov, J. Chem. Phys. 122, 034104 (2005)]. Recently, ...

PubMed

23
Hard scaling challenges for ab initio molecular dynamics capabilities in NWChem: Using 100,000 CPUs per second
2010-09-16

An overview of the parallel algorithms for ab initio molecular dynamics (AIMD) used in the NWChem program package is presented, including recent developments for computing exact exchange. These algorithms make use of a two-dimensional processor geometry proposed by Gygi et al for use in AIMD algorithms. Using this strategy, a highly ...

Energy Citations Database

24
Tautomeric equilibria of 3-formylacetylacetone: low-temperature NMR spectroscopy and ab initio calculations.
2009-07-01

Keto-enol tautomerization of 3-formylacetylacetone has been studied by NMR spectroscopy, ab initio, and DFT calculations in the gas phase and continuum solvation. By employing very low temperatures in a freonic solvent, tautomeric and conformational equilibria in the slow exchange regime were analyzed in detail. The beta-tricarbonyl ...

PubMed

25
Catalysis of nanotube plasticity under tensile strain
2002-11-01

We have performed ab initio simulations to investigate the effect of carbon adatoms on the plastic deformation of carbon nanotubes. Under applied stress, the system spontaneously undergoes a Stone-Wales transformation catalyzed by the exchange of the adatom with a substrate atom. The unraveled mechanism reduces the barrier by a factor ...

NASA Astrophysics Data System (ADS)

26
Ab initio molecular-dynamics method based on the restricted path integral: Application to the electron plasma and liquid alkali metal
1998-09-01

We introduce an ab initio molecular-dynamics method based on the discretized path-integral representation of quantum particles. Fermi statistics is automatically generated by an effective exchange potential. This path-integral molecular-dynamics method is able to simulate electron plasmas at the border of the degenerate and the ...

NASA Astrophysics Data System (ADS)

27
Ab initio calculations of the atomic and electronic structure of MgF2 (011) and (111) surfaces
2011-04-01

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 ...

NASA Astrophysics Data System (ADS)

28
Nonlocal exchange effects in zigzag-edge magnetism of neutral graphene nanoribbons
2011-04-01

We study the role of nonlocality of exchange in a neutral zigzag graphene nanoribbon within the ?-orbital unrestricted Hartree-Fock approximation. Within this theory we find that the magnetic features are further stabilized for both the intraedge and interedge exchange as compared to mean-field theories of zigzag ribbons based on local ...

NASA Astrophysics Data System (ADS)

29
Ab-Initio Simulation of a/2110> Screw Dislocations Gamma ...
2004-11-01

... AB-INITIO SIMULATION OF a/2110> ... 4. TITLE AND SUBTITLE AB-INITIO SIMULATION OF a/2110> SCREW DISLOCATIONS γ-TiAl 5c. ...

DTIC Science & Technology

30
Ab Initio Study on Spin Polarization of III-V Compound Tips
1998-06-01

... ADP012740 TITLE: Ab Initio Study on Spin Polarization of III-V Compound Tips ... Ab initio study on spin polarization of III-V compound tips ...

DTIC Science & Technology

31
AB Initio and Calphad Thermodynamics of Materials.
2004-01-01

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...

National Technical Information Service (NTIS)

32
40 CFR 86.004-30 - Certification.
2009-07-01

...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

33
Collision-induced spin exchange of alkali-metal atoms with H3e : An ab initio study
2009-06-01

We present a rigorous quantum study of spin-exchange transitions in collisions of the alkali-metal atoms with H3e in the presence of an external magnetic field. Using accurate ab initio interaction potentials, we obtain refined estimates for the Fermi contact interaction constants for complexes of Na, K, and Rb atoms with H3e . ...

NASA Astrophysics Data System (ADS)

34
Ab initio evaluation of Coulomb and exchange parameters for DFT+U calculations
2007-10-01

Conventional density functional theory (DFT) fails for materials with strongly correlated electrons, such as late transition metal oxides. Large errors in the intra-atomic Coulomb and exchange interactions are the source of this failure. The DFT+U method has provided a means, through empirical parameters, to correct these errors. Here, we present a systematic ...

NASA Astrophysics Data System (ADS)

35
Ab initio molecular dynamics study of the hydrogen-deuterium exchange in bulk lithiumborohydride (LiBH4)
2009-04-01

The hydrogen storage is still a challenge for mobile applications. The diffusion of hydrogen in solids is considered as a general model system but there is limited knowledge available for the dynamics of hydrogen in complex hydrides. In this letter, we present a systematic approach to study the hydrogen-deuterium exchange in bulk LiBH4 based on ab ...

NASA Astrophysics Data System (ADS)

36
Ab initio molecular dynamics simulation of pressure-induced phase transformation in BeO
2011-01-01

Ab initio molecular dynamics (MD) method has been used to study high pressure-induced phase transformation in BeO based on the local density approximation (LDA) and the generalized gradient approximation (GGA). Both methods show that the wurtzite (WZ) and zinc blende (ZB) BeO transforms to the rocksalt (RS) structure smoothly at high pressure. The ...

Energy Citations Database

37
ab-Initio Molecular Dynamics Simulations of Molten Ni-Based ...
2007-06-01

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

DTIC Science & Technology

38
Overview of Molecular Modelling and Ab initio Molecular ...
2000-09-01

... from federally funded research, testing and training ... for Research Development Test and Evaluation ... of Molecular Modelling and Ab initio Molecular ...

DTIC Science & Technology

39
New AB Initio Based Density Functional Methods for ...
2000-05-31

... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : New AB Initio Based Density ...

DTIC Science & Technology

40
Development of Ab-initio Multibody Energy Expansions for the ...
2010-10-31

... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Development of Ab-initio Multibody ...

DTIC Science & Technology

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41
Comparison of Single Point Ab initio Energies Calculated ...
1989-04-01

... Ab initio Energies Calculated Using 3 ... of the Transition States (TS ... Descriptors : *TRANSITIONS, *MOLECULES, COMPUTATIONS, COMPARISON ...

DTIC Science & Technology

42
An ab initio QCISD Study of the Potential Energy Surface for ...
1998-09-01

... Abstract : Results are presented from ab initio quantum chemical calculations on the ground state potential energy surface for the open shell ...

DTIC Science & Technology

43
An Ab Initio Study of Solid Nitromethane, HMX, RDX, and ...
2004-12-01

... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... Title : An Ab Initio Study of Solid ...

DTIC Science & Technology

44
An AB Initio Study of Dimethyl Nitramine.
1987-08-01

... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : An AB Initio Study of Dimethyl ...

DTIC Science & Technology

45
Ab-initio Simulations of Molten Ni Alloys
2010-04-01

... Accession Number : ADA523968. Title : Ab-initio Simulations of Molten Ni Alloys. Descriptive Note : Journal article (preprint). ...

DTIC Science & Technology

46
Ab-Initio Molecular Dynamics Simulations of Molten Ni-Based ...
2007-06-01

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

DTIC Science & Technology

47
Ab-Initio Molecular Dynamics Simulations of Molten Ni-Based ...
2008-07-01

... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab-Initio Molecular Dynamics Simulations ...

DTIC Science & Technology

48
Ab-Initio MODPOT/VRDDO/MERGE Calculations on Energetic ...
1981-10-15

... We carried out ab-initio quantum chemical calculations on these energetic cyclic ethers and generated the electrostatic molecular potential contour ...

DTIC Science & Technology

49
Ab initio quantum chemical techniques have been used to ...

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

50
Ab Initio and DFT Potential Energy Surfaces for Cyanuric ...
1998-07-01

... Accession Number : ADA351780. Title : Ab Initio and DFT Potential Energy Surfaces for Cyanuric Chloride Reactions. Descriptive Note : Final rept. ...

DTIC Science & Technology

51
Ab Initio Study on Atomic Structures and Physical Properties of ...
2009-11-25

... Ab initio study on atomic structures and physical properties of CdSe quantum nanodots ... Figure 2. Diagram of covered nanodots. ...

DTIC Science & Technology

52
Ab Initio Study on Atomic Structures and Physical Properties of ...
2009-11-25

... Title : Ab Initio Study on Atomic Structures and Physical Properties of CdSe Quantum Nanodots. Descriptive Note : Final rept. ...

DTIC Science & Technology

53
Ab Initio Study of the Structure, Vibrational Frequencies and ...
1995-06-01

... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : Ab Initio Study of the Structure ...

DTIC Science & Technology

54
Ab Initio Study of the Electric Dipole Transition Moment for the ...
1990-12-01

... Rydberg I 'Flu state. Demoulin and Jungen (1974) used an ab initio quantum chemical approach, but only at the SCF level ...

DTIC Science & Technology

55
Ab Initio Study of the Electric Dipole Transition Moment for the ...
1990-12-01

... moment has been cancelled a priori for the electronic transition as a function of R(CC), using ab initio quantum chemical techniques including state ...

DTIC Science & Technology

56
Ab Initio Study of Ultracold Polar Molecules in Optical Lattices

... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... Title : Ab Initio Study of Ultracold ...

DTIC Science & Technology

57
Ab Initio Studies on Hexavalent Phosphorus Compounds
2002-01-01

1 AB INITIO STUDIES ON HEXAVALENT PHOSPHORUS COMPOUNDS Ashley L. Wilson* Aberdeen High School Aberdeen, Maryland 21001 ...

DTIC Science & Technology

58
Ab Initio Studies on Hexavalent Phosphorus Compounds
2002-01-01

... Accession Number : ADA436055. Title : Ab Initio Studies on Hexavalent Phosphorus Compounds. Descriptive Note : Conference paper. ...

DTIC Science & Technology

59
Ab Initio Relativistic Study of Formation of Ultracold Polar ...
2006-01-31

... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : Ab Initio Relativistic Study of ...

DTIC Science & Technology

60
Ab Initio Quantum Chemical Study of Electron Transfer in ...

... Accession Number : ADA440631. Title : Ab Initio Quantum Chemical Study of Electron Transfer in Carboranes. Descriptive Note : Journal article. ...

DTIC Science & Technology

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61
Ab Initio Potential Energy Surface for the H + OCS Reaction
1993-10-01

... Accession Number : ADA270577. Title : Ab Initio Potential Energy Surface for the H + OCS Reaction. Descriptive Note : Final rept. ...

DTIC Science & Technology

62
Ab Initio Potential Energy Surface for H + OCS Reactions ...
1994-11-01

... [2"- ARMY RESEARCH LABORATORY [C Ab Initio Potential Energy Surface for H + OCS Reactions: Extended Basis Sets ...

DTIC Science & Technology

63
Ab Initio Potential Energy Surface for H + OCS Reactions ...
1994-11-01

... 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. ...

DTIC Science & Technology

64
Ab Initio Direct Trajectory Simulation on Hydrogen Atom ...
2006-07-14

... Ab initio direct trajectory simulation on hydrogen atom transfer in 7-azaindole in the electronic excited state with assist of water molecules ...

DTIC Science & Technology

65
Ab Initio Direct Trajectory Simulation on Hydrogen Atom ...
2006-07-14

... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab Initio Direct Trajectory Simulation on ...

DTIC Science & Technology

66
Ab Initio Calculation of Vibrational Circular Dichroism Spectra ...
1996-02-01

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

DTIC Science & Technology

67
Ab Initio Calculation of Intermolecular Potential Parameters for ...
2000-08-01

... from federally funded research, testing and training ... for Research Development Test and Evaluation ... Title : Ab Initio Calculation of Intermolecular ...

DTIC Science & Technology

68
AB Initio Propagator Theory of Clusters
2003-02-12

... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : AB Initio Propagator Theory of ...

DTIC Science & Technology

69
Ab Initio Calculations of Water Line Strengths
1998-01-01

We report on the determination of a high quality ab initiu potential energy surface (PES) and dipole

NASA Technical Reports Server (NTRS)

70
Mechanistic studies of electron exchange kinetics using ab initio
1981-01-01

The rate constant for the aqueous Fe2(+)-Fe3(+) electron exchange reaction is calculated. The effective contact distance (r sub min) is taken as 5.5 A, the value at which the staggered face-to-face configuration of the orthohedral complexes achieves van der waals contact. The electronic coupling information implicit K sub el(r) is obtained from large scale ...

NASA Astrophysics Data System (ADS)

71
Impact ionization in GaAs: A screened exchange density-functional approach
2001-08-13

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

DOE Information Bridge

72
Exact-exchange density functional theory for neutron drops
2011-07-01

We compute the ground-state properties of finite systems of neutrons in an external harmonic trap, interacting via the Minnesota potential, using the �exact-exchange� form of orbital-dependent density functional theory. We compare our results with Hartree-Fock calculations and find very close agreement. Within the context of the interaction studied, we conclude that this ...

NASA Astrophysics Data System (ADS)

73
Determination of Highly Accurate Heats of Formation
1996-01-01

Two approaches for directly computing a molecular heat of formation based on sophisticated ab initio

NASA Technical Reports Server (NTRS)

74
Ab Initio Studies of Stratospheric Ozone Depletion Chemistry
1995-01-01

An overview of the current understanding of ozone depletion chemistry, particularly with regards the

NASA Technical Reports Server (NTRS)

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