Main View
This view is used for searching all possible sources.
First Page Previous Page 1 2 3 4 Next Page Last Page
 
1
Ab initio electronic structure study for TTF-TCNQ under uniaxial compression
2004-04-01

We have investigated the electronic structure of TTF-TCNQ under uniaxial compression with ab initio plane-wave pseudopotential calculations within the local-density approximation and generalized gradient approximation. Depending on the compression direction, the constituent molecules are deformed in different ways. ...

NASA Astrophysics Data System (ADS)

2
Chemistry of H2O and HF Under Extreme Conditions.
2005-01-01

The predicted high pressure superionic phases of water and HF are investigated via ab initio molecular dynamics. These phases could potentially be achieved through either static compression with heating or through shock compression. We study water at dens...

National Technical Information Service (NTIS)

3
Ideal shear strength under compression and tension in C, Si, Ge, and cubic SiC: an ab initio density functional theory study.
2011-09-08

Ideal shear strength under superimposed normal stress of cubic covalent crystals (C, Si, Ge, and SiC) is evaluated by ab initio density functional theory calculation. Shear directions in [[Formula: see text

PubMed

4
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

5
Exploring Structural Bond Energy Release (SBER) in Nanodiamonds Using Quantum Molecular Dynamics and Static High Pressure.
2008-01-01

We present a combined experimental and theoretical study on carbon nanodiamonds using Raman and DAC experimentation and ab initio calculations. Our calculations confirm the surface reconstruction to a fullerene-like structure, and indicate compression of ...

National Technical Information Service (NTIS)

6
Ab initio calculations of the phonon frequencies and related properties of crystalline Ne under pressure
2009-10-01

Ab initio theoretical investigations of the dynamics and thermodynamics of a compressed Ne crystal performed using a model that explicitly takes account of the deformation of the electronic shells in the dipole approximation are presented. A dynamical matrix based on a non-empirical short-range repulsive potential and integration over ...

NASA Astrophysics Data System (ADS)

7
Equation of State for Mg2SiO4 (?-forsterite, ?-wadsleyite and ?-ringwoodite): ab-Initio
2011-07-01

The compression of Mg2SiO4, (?-forsterite, ?-wadsleyite and ?-ringwoodite) up to 24 GPa pressure is analysed with the help of two equation of state :first Birch-Murnaghan and second based on ab-initio pseudopotential approach. It is concluded that the EOS based on ab-initio pseudopotential approach show the systematic ...

NASA Astrophysics Data System (ADS)

8
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

9
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

10
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

11
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

12
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

13
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

14
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

15
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)

16
Structural phase transitions in Ruddlesden-Popper phases of strontium titanate: {\\em ab initio} and inhomogeneous Ginzburg-Landau approaches
2010-08-20

We present the first systematic {\\em ab initio} study of anti-ferrodistortive (AFD) order in Ruddlesden-Popper (RP) phases of strontium titanate, Sr$_{1+n}$Ti$_n$O$_{3n+1}$, as a function of both compressive epitaxial strain and phase number $n$. We find all RP phases to exhibit AFD order under a significant range of strains, ...

E-print Network

17
Structural phase transitions in Ruddlesden-Popper phases of strontium titanate: Ab initio and modulated Ginzburg-Landau approaches
2010-11-01

We present a systematic ab initio study of antiferrodistortive (AFD) order in Ruddlesden-Popper (RP) phases of strontium titanate, Sr1+nTinO3n+1 , as a function of both compressive epitaxial strain and phase number n . We find all RP phases to exhibit AFD order under a significant range of strains, recovering the AFD order of bulk ...

NASA Astrophysics Data System (ADS)

18
Absolute deformation potentials and robust ab initio model for band shifts induced by (001) biaxial strain in group IIIA-VA semiconductors
2011-01-01

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 initio full ...

NASA Astrophysics Data System (ADS)

19
Ab initio Molecular Dynamics Simulations of Water Under Static and Shock Compressed Conditions
2007-07-25

We report herein a series of ab initio simulations of water under both static and shocked conditions. We have calculated the coherent x-ray scattering intensity of several phases of water under high pressure, using ab initio Density Functional Theory (DFT). We provide new atomic scattering form factors for water at ...

DOE Information Bridge

20
Coupling of ab initio density functional theory and molecular dynamics for the multiscale modeling of carbon nanotubes.
2008-01-14

A multiscale technique is developed that couples empirical molecular dynamics (MD) and ab�initio density functional theory (DFT). An overlap handshaking region between the empirical MD and ab�initio DFT regions is formulated and the interaction forces between the carbon atoms are calculated based on the second-generation reactive empirical bond order ...

PubMed

First Page Previous Page 1 2 3 4 Next Page Last Page
 
First Page Previous Page 1 2 3 4 Next Page Last Page
 
21
Ab initio calculations of the thermodynamic properties of LiF crystal
2011-01-01

This paper presents results obtained in ab initio calculations of the thermodynamic properties of B1 and B2 lithium fluoride under pressure. The data were used to calculate LiF isotherms and isochors at pressures from 0 to 500 GPa and temperatures up to the melting point. Calculated results are compared with available theoretical and experimental data on ...

NASA Astrophysics Data System (ADS)

22
Ultrafast transformation of graphite to diamond: An ab initio study of graphite under shock compression
2008-05-01

We report herein ab initio molecular dynamics simulations of graphite under shock compression in conjunction with the multiscale shock technique. Our simulations reveal that a novel short-lived layered diamond intermediate is formed within a few hundred of femtoseconds upon shock loading at a shock velocity of 12 km/s (longitudinal ...

NASA Astrophysics Data System (ADS)

23
Ultrafast transformation of graphite to diamond: an ab initio study of graphite under shock compression.
2008-05-14

We report herein ab initio molecular dynamics simulations of graphite under shock compression in conjunction with the multiscale shock technique. Our simulations reveal that a novel short-lived layered diamond intermediate is formed within a few hundred of femtoseconds upon shock loading at a shock velocity of 12 kms (longitudinal ...

PubMed

24
Nano-Plasticity of Single-Wall Carbon Nanotubes Under Uniaxial Compression.
1999-01-01

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

National Technical Information Service (NTIS)

25
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

26
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

27
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)

28
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

29
Probing of the hydrogen melting line at high pressures by dynamic compression
2008-06-09

We investigate the capabilities of dynamic compression by intense heavy ion beams to yield information about the high pressure phases of hydrogen. Employing ab initio simulations and experimental data, a new wide range equation of state for hydrogen that covers solid, fluid, gas and plasma phases has been constructed for our ...

Energy Citations Database

30
Formation of an anataselike phase in silica under anisotropic stress: An ab initio constant-pressure study
2009-07-01

We study the behavior of ? cristobalite under anisotropic stresses using constant-pressure ab initio simulations and observe the formation of the anataselike, stishovite, and CaCl2 -type structures depending on the degree of hydrostatic compression. These phase transformations proceed via a tetragonal intermediate phase (phase X-I) ...

NASA Astrophysics Data System (ADS)

31
Ab initio based force field and molecular dynamics simulations of crystalline TATB.
2004-04-15

An all-atom force field for 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is presented. The classical intermolecular interaction potential for TATB is based on single-point energies determined from high-level ab initio calculations of TATB dimers. The newly developed potential function is used to examine bulk crystalline TATB via molecular dynamics ...

PubMed

32
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

33
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

34
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

35
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

36
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

37
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

38
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

39
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

40
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

First Page Previous Page 1 2 3 4 Next Page Last Page
 
First Page Previous Page 1 2 3 4 Next Page Last Page
 
41
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

42
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

43
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

44
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

45
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

46
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

47
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

48
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

49
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

50
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

51
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

52
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

53
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

54
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

55
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

56
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

57
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

58
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

59
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

60
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

First Page Previous Page 1 2 3 4 Next Page Last Page
 
First Page Previous Page 1 2 3 4 Next Page Last Page
 
61
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

62
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

63
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

64
Quasihydrostatic equation of state of iron above 2 Mbar.
2006-11-22

The compression curve of iron is measured up to 205 GPa at 298 K, under quasihydrostatic conditions in a diamond anvil cell. Above 150 GPa, the compression of this metal is significantly higher than previously measured under nonhydrostatic conditions. The same compression curve is also calculated ab ...

PubMed

65
Quantum conductance modulation in graphene by strain engineering
2010-04-01

Ab initio study reveals that strain can influence graphene's ballistic conductance substantially; however, the effect of biaxial strain is significantly different from that of hydrostatic strain. For hydrostatic strain, tension increases conductance while compression decreases conductance. In contrast, when biaxial ...

NASA Astrophysics Data System (ADS)

66
Static ion structure factor for dense plasmas: Semi-classical and ab initio calculations
2010-09-01

We calculate the static structure factor of dense multi-component plasmas. Large scale ab initio finite-temperature DFT molecular dynamics simulations are performed in order to cover the region where a consistent quantum treatment for the electrons is inevitable. Especially, the behavior at small wave numbers k can be inferred from the relation to the ...

NASA Astrophysics Data System (ADS)

67
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)

68
Z. Phys. D 40, 282�287 (1997) ZEITSCHRIFT

and compression cycles is studied. Ab-initio local- spin-density functional based molecular dynamics simula- tions the Born-Oppenheimer Local-Spin-Density Functional Molecular-Dynamics (BO-LSD-MD) method [28] in inves confining the electrons in the wire is short-ranged (as also found in recent local density functional

E-print Network

69
The cold equation of state of tantalum
2009-01-01

In high-pressure isentropic compression experiments (ICE), the pressure is dominated by the cold curve. In order to obtain an accurate semi-empirical cold curve for Ta, we calculate the thermal pressure from ab initio phonon and electronic excitation spectra. The cold curve is then inferred from ultrasonic and shock data. Our empirical ...

Energy Citations Database

70
Stability of the Si lattice: electron-phonon interactions and superconductivity in hexagonal Si
1986-08-01

Using ab initio pseudopotentials the properties of electrons, phonons and electron-phonon interactions in highly compressed Si have been computed. In particular, the hexagonal phases have been predicted to be superconducting by this calculation. The superconducting transition temperature for hexagonal Si has been measured for pressures ...

Energy Citations Database

71
Anisotropic Nanomechanics of Boron Nitride Nanotubes: Nanostructured 'Skin' Effect.
2000-01-01

The stiffness and plasticity of boron nitride nanotubes are investigated using generalized tight-binding molecular dynamics and ab-initio total energy methods. Due to boron-nitride BN bond buckling effects, compressed zigzag BN nanotubes are found to unde...

National Technical Information Service (NTIS)

72
Ab Initio Simulations of Nano-Diamond Surface Reconstruction
2008-03-01

We have simulated with in the Density Functional Theory (DFT) spherically cut nano-diamonds from bulk diamond at ambient conditions. The 2.6 nanometer diameter sphere is then allowed to relax at 250K and surface reconstruction is observed. Four hemispherical fullerene like regions form on the surface and while the interior maintains the diamond structure, it undergoes ...

NASA Astrophysics Data System (ADS)

73
The Cold Equation of State of Tantalum
2009-12-01

In high-pressure isentropic compression experiments (ICE), the pressure is dominated by the cold curve. In order to obtain an accurate semi-empirical cold curve for Ta, we calculate the thermal pressure from ab initio phonon and electronic excitation spectra. The cold curve is then inferred from ultrasonic and shock data. Our empirical ...

NASA Astrophysics Data System (ADS)

74
Energy dissipation via quantum-chemical hysteresis during high-pressure compression: A first-principles molecular dynamics study of phosphates

. All ab initio molecular dynamics simulations were performed with the CPMD program.13 Density func and Ernzerhof.14 Core electrons on all atoms were represented by norm- conserving pseudopotentials15). 13 J. H�utter et al., CPMD, Copyright IBM Z�urich Research Laboratory and MPI f�ur Festk

E-print Network

75
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)

76
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)

First Page Previous Page 1 2 3 4 Next Page Last Page