... We carried out ab-initio quantum chemical calculations on these energetic cyclic ethers and generated the electrostatic molecular potential contour ...
DTIC Science & Technology
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)
Ab initio quantum chemistry methods are used to study the energetics of interactions of O atoms with
NASA Technical Reports Server (NTRS)
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 other way, more involved, is the ...
DOE Information Bridge
... Energetic polymers, Oxetanes, Quantum Chemical calculations, Configuration ... MRD/CI), Energetic compounds, Ab-initio potential functions, Crystal ...
... Keywords: ab initio calculations · energetic materials · ionic liquids · lanthanides · nitrate complexes ... Page 9. Lanthanide-Based Ionic Liquids ...
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;...
... used successfully the strategy for ab-initio MRD-CI ... polymerization; Energetic polymers; Oxetanes; Quantum chemical calculations; Configuration ...
The object of this research is to characterize the energetics, spectroscopic properties, and elementary chemical reactions of molecular ions. The approach used will exploit recent developments in ab initio molecular quantum mechanics. Some of the systems ...
The objective of this research was to investigate fundamental aspects of the fracture and deformation behavior of ordered intermetallic aerospace alloys on the basis of the ab-initio determination of the parameters needed for further (1) model theoretical...
The structure and energetics of free radicals, ions, and clusters have been investigated by photoelectron photoion coincidence (PEPICO) and analyzed with the aid of ab initio molecular orbital and statistical theory (RRKM) calculations. The two major them...
The structure and energetics of free radicals, ions, and clusters have been investigated by photoelectron photoion coincidence (PEPICO) and analyzed with ab initio molecular orbital and statistical theory RRKM calculations. In these experiments, molecules...
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 ...
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 ...
NASA Astrophysics Data System (ADS)
The reaction of C(3P) with H2S to HCS/HSC isomers is investigated with high level ab initio methods. Besides reaction energies to form HCS/HSC, the energetics and properties of different singlet/triplet H2CS reaction intermediates are studied. The combination of ab initio theory and crossed ...
Ab-initio quantum chemical investigations of the mechanism of cationic polymerization; Development, implementation testing of theoretical procedures for prediction of crystal structures and densities; Ab-initio quantum chemical MODPOT/VRDDO/MERGE calculat...
Contents: Ab-initio quantum chemical investigations of the mechanism of cationic polymerization; Development of theoretical procedures for prediction of crystal structures and densities; Ab-initio quantum chemical MODPOT/VRDDO/MERGE calculations on nitro-...
Results of ab initio molecular orbital calculations are reported for complexes of eleven anions with a water molecule. Optimized geometries obtained with the 6-31G(d) basis set were used in calculations including diffuse functions and the correlation energy. The present structural and energetic results complement and extend ...
Energy Citations Database
The geometries and energetics of 16 aromatic hydrocarbons are obtained from ab initio molecular orbital calculations at the 6-31G{sup *} SCF level. The energies are used to derive group equivalents that enable calculation of accurate heats of formation. Several applications of the group equivalents are described.
There has been an interest in the study of hydrogen ion clusters. However, only positive clusters, Hn +, where n = 3m 5, 7, ..., have been discovered and successfully analyzed by meand of both experimental and ab initio theoretical methods (cf. Hirao and ...
An ab initio quantum-chemical study has been made of the possible existence in terms of structural and thermodynamic stabilities of the pentacoordinated nitrogen hydrides and fluorides, NF(n)H(5-n) for n=0 to 5. Three structurally stable species have been...
Ab Initio QM/MM Study of Class A -Lactamase Acylation: Dual Participation of Glu166 and Lys73 ) and an energetically favorable transfer of a proton from Lys73 to Glu166, through the catalytic water molecule and Ser70. This gives unprotonated Lys73 and protonated Glu166. Tetrahedral formation ensues in a concerted
E-print Network
Quantum mechanical-based (or ab initio) methods are used to predict the stability properties of materials although their application is limited to relatively simple systems in terms of structures and number of alloy components. However thermodynamics of complex multi-component alloys requires a more versatile approach afforded within the CALPHAD formalism. ...
The objectives of this work which were fulfilled were to (1) use high level ab initio molecular orbital theory to predict the structures and energies of potential energetic molecules and to guide the synthesis of the more promising candidate molecules, (2...
In the research on part I of this project we are carrying out ab-initio quantum chemical calculations and generating electrostatic molecular potential maps for cationic polymerization: on energetic monomers, on their interaction with catalysts and on the ...
This final report describes the initial two phases of the overall project. In the first phase, accurate barriers and energetics were calculated for 7 reactions involved in O(3P) oxidation of hydrocarbons. This was done by MRCI/CASSCF ab initio calculation...
Contents of this report include: Conversion of Our Programs to CRAY Vector Supercomputers; Calculations for Cationic Polymerization of Energetic Monomers; MRD-CI Calculations on Decomposition Pathways of Energetic Nitrocompounds; POLY-CRYST; Ab-Initio Ato...
... This study involves: Ab-initio crystal orbitals and polymer orbitals; Ab-initio coupled cluster program; Ab-initio quantum chemical calculations and ...
For the equilibrium immiscible Fe-Cu system, ab initio calculations using the projector augmented wave method identify the relatively stable structures of the metastable Fe25Cu75 and Fe50Cu50 alloys to be both of fcc and determine their corresponding lattice constants and cohesive energies. Some of the ab initio ...
... Title : Chalcopyrite Magnetic Semiconductors: An Ab-Initio Study of Their Structural, Electronic and Magnetic Properties. ...
... from federally funded research, testing and training ... for Research Development Test and Evaluation ... COMPENDIUM OF AB INITIO CALCULATIONS ...
... Accession Number : ADA219907. Title : An Ab Initio Study of the Geometry and Rotational Barrier of 4- Phenylimidazole. ...
... from federally funded research, testing and training ... and agencies for Research Development Test and Evaluation ... Title : Ab Initio Calculations of the ...
... Title : Ab Initio Calculation of Vibrational Absorption and Circular Dichroism Spectra Using Density Functional Force Fields. ...
... Title : AB Initio Quantum Chemical Investigations of Solubilities in Supercritical Solutions. Descriptive Note : Conference Paper,. ...
We have performed extensive ab initio and classical MD simulations of benzene in water in order to examine the unique solvation structures that are formed. Qualitative differences between classical and ab initio MD simulations are found and the importance of various technical simulation parameters is examined. Our ...
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 ...
An ab initio study based on local-density-functional (LDF) theory is presented for the chemisorption of hydrogen on the Pd(111) surface. Our calculation uses the Vienna ab initio molecular-dynamics program (VAMP) based on (i) finite-temperature LDF, (ii) exact calculation of the electronic ground state and ...
The authors analyze the implications of the recently reported results of ab initio calculations of formation energies of the Fe-Cr alloy. The formation energies show a change in sign from negative to positive as Cr composition increases above {approx}10%. By developing a classic potential to evaluate the thermodynamic properties, they determine the ...
Motivated by the state of the art method for producing boron nitride nanotubes in which magnesium has been speculated to act as a catalyst, we study the elemental chemistry of boron and nitrogen on the Mg(0001) surface using ab initio methods. We do this by considering the energetics of individual boron and nitrogen atoms, and the ...
Using ab initio density-functional theory, we study the role of interstitial hydrogen on the energetics of the phase transformation of iron from bcc to hcp along Bain�s pathway. The impurity creates an internal stress field that can be released through a tetragonal distortion of the lattice, promoting the bcc (ferromagnetic) ? fcc ...
This report pertains to: New Program Developments on the CRAY Supercomputer, MRD-CI Calculations for Cationic Polymerization of Energetic Oxetanes, Ab-Initio MRD-CI Calculations for Breaking a Chemical Bond in a Molecule in a Crystal or Other Solid Enviro...
This paper discusses: Program Enhancements and New Program Developments on the CRAY Supercomputer; MRD-CI Calculations for Cationic Polymerization of Energetic Oxetanes; Ab-Initio MRD-CI Calculations for Breaking a Chemical Bond in a Molecule in a Crystal...
Experimentally it had been observed in 1969 for cyclic ethers with conventional substituents that their propensity to polymerize was influenced by their basicities and ring strain. For energetic new polymers it was desired to predict their propensity to p...
... 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
The energetic and electronic structure of bilayered graphene (BLG) with AA stacking arrangement on a SiO2 substrate is investigated in the presence of an electric field F of different intensities by ab initio density functional calculations. The AA-stacked bilayer graphene is stable on the SiO2 substrate in the absence of an electric ...
This paper presents the thermochemical properties of 42 energetic materials commonly used in explosives and/or propellants. The standard enthalpies of formation at 298.15 K and heat capacities and entropies in the temperature range of 300-5000 K have been computed by means of the density functional theory in quantum chemistry along with a protocol developed for these ...
Molecular mechanics valence force field parameters for the sulfonamide group, SO[sub 2]NH, have been derived from ab initio calculations at the RHF/6-31G* level of theory. The force field parameters were designed to be used in conjunction with existing parameters from the MM2/MMP2 force field. The new parameters are demonstrated to accurately reproduce the ...
Using ab initio density functional calculations, we study the microscopic mechanism of hydrogen release from ammonia borane (NH3BH3) and the reverse process leading to its subsequent recharging with hydrogen. Our total energy surfaces indicate the most favorable pathways to thermally convert the NH3BH3 molecular solid to the ...
Molecular dynamics simulations of NO-doped Ar solid upon Rydberg photoexcitation of the impurity have been carried out taking into account angular dependent potential energy surfaces (PESs) in the ground and excited states. To go beyond isotropic potentials simulations, the effects of anisotropy of potentials on the structure, dynamics, and energetics are investigated by ...
... 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 ...
...with this part. The certificate shall be void ab initio for those vehicles causing the...issued, and the certificate may be deemed void ab initio. (C) The manufacturer...with this part. The certificate shall be void ab initio for those vehicles causing...
Code of Federal Regulations, 2010
The bonding in O{sub 3}M-M(CO){sub 5} has been studied by ab initio SCF, two-configuration SCF, and CI methods for M = Re and Tc. Calculations indicate that these complexes are highly polar. The nature of the charge transfer in these complexes is considered.
The influence of Ti and Zr impurity atoms on the atomic and electronic structures of a mesoporous SiO2 matrix is ab initio simulated in a generalized gradient approximation. Energetically favorable positions of titanium and zirconium in the structure are revealed. The incorporation of Zr and Ti ions is shown to decrease the bandgap.
The structures of protonated pentazole cations (RN5H(+)), oxygen- containing anions such as N(NO2)2(-), NO3(-), and ClO4(-), and the corresponding ion pairs are investigated by ab initio quantum chemistry calculations. The stability of the pentazole catio...
The reaction pathways of deprotonation versus nucleophilic substitution involving mPGES-2 enzyme catalysis were investigated by ab initio molecular orbital theory calculations for the reaction of methylthiolate with the endoperoxide core of PGH(2) and by the combined quantum mechanical molecular mechanical methods. The calculations showed that ...
Progress are reported on: electronic structure of PdO, PtO, and AgO (band structure calculations); ab initio calculations of electronic structure of TiO(sub 2)(110) surface; and electronic structure of VO(sub 2) and TiO(sub 2) thin films and multilayers. ...
Progress are reported on: electronic structure of PdO, PtO, and AgO (band structure calculations); ab initio calculations of electronic structure of TiO{sub 2}(110) surface; and electronic structure of VO{sub 2} and TiO{sub 2} thin films and multilayers. (DLC)
Ab initio molecular orbital theory has been used to evaluate several chemical systems. The applicability of the current standard models has been explored. Within the Hartree-Fock self-consistent-field (SCF) and configuration interaction (CI) approaches, t...
We comment on some new'' results concerning the energetics of W(100) reconstruction. They, in fact, reproduce our former results, obtained in a semiempirical tight-binding scheme, assuming from {ital ab} {ital initio} calculations a {ital d}-band filling of 4.4, which concluded in favor of a multilayer nature of ...
Using the Kernel Energy Method we apply ab initio quantum mechanics to study the relative importance of weak and strong interactions (including hydrogen bonds) in the crystal structures of the title compounds TDA1 and RangDP52. Perhaps contrary to widespread belief, in these compounds the weak interaction energies, because of their large number and ...
PubMed Central
deposition on Al(111) - STM FOV: 23 nm. Ti/Al(111) deposited at 400 K. #12;10 FT-IR Spectroscopy - atomic H, time-resolved, high-pressure. � X-ray microprobe � IR micro-spectroscopy � Surface microscopy & energetics. Ab-initio molecular dynamics - surface dynamics. FT-infrared reflection spectroscopy - hydrogen
We report an ab initio study of pressure-induced amorphization (PIA) in zeolites, which are model systems for this phenomenon. We confirm the occurrence of recently reported low-density amorphous phases that preserve the crystalline topology, and explain the role of the zeolite composition regarding PIA. Our results support the correctness of existing ...
It is now possible to calculate many properties including the energetics (total bond dissociation energies or heats of formation) of molecules containing light elements to high accuracy by using correlation-consistent basis sets, coupled cluster theory an...
The structures of protonated pentazole cations (RN5H+), oxygen- containing anions such as N(NO2)2-, NO3-, and ClO4-, and the corresponding ion pairs are investigated by ab initio quantum chemistry calculations. The stability of the pentazole cation is exp...
... 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 ...
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 ...
We present a comparative ab initio survey of possible dissociation products of NH3 , PH3 , and AsH3 on the Si(001) surface. In agreement with previous studies, we find that the relative energetics of XH3 and XH2 species ( X=N , P , As ) are common across all three systems. In contrast, the energetics of ...
Resolving chemical dynamics of decomposition of energetic molecules is crucial for understanding detonation initiation in energetic materials and predicting their sensitivity to shock and impact stimuli. We employ Born-Oppenheimer molecular dynamics driven by density-functional methods to identify possible decomposition pathways in nitric esters (including ...
Molecular dynamics simulations were performed using a modified amoeba force field to determine hydration and dynamical properties of the divalent cations Ca2+ and Mg2+. The extension of amoeba to divalent cations required the introduction of a cation specific parametrization. To accomplish this, the Thole polarization damping model parametrization was modified based on the ab ...
Molecular dynamics simulations were performed using a modified amoeba force field to determine hydration and dynamical properties of the divalent cations Ca2+ and Mg2+. The extension of amoeba to divalent cations required the introduction of a cation specific parametrization. To accomplish this, the Thol� polarization damping model parametrization was modified based on the ...
We present investigations of interactions of explosive molecules RDX and TATP with metal organic framework MOF-5, using DFTY based ab-initio simulation method FIREBALL. Energetics studies in bulk shows that only one of the binding sites of RDX in MOF-5 suggested by quantum chemistry calculations confirm. The absorption site is on a linker of the framework ...
We revive intriguing, yet still unexplained, experimental results of Ehrlich and co-workers [Phys. Rev. Lett. 77, 1334 (1996)10.1103/PhysRevLett.77.1334; Phys. Rev. Lett. 67, 2509 (1991)10.1103/PhysRevLett.67.2509] who have observed, that 5d adatoms distributed on (111) surface islands of 5d metals favor the adsorption at the cluster�s edge rather than at the cluster�s interior, which lies ...
Quantum-mechanical molecular dynamics have been used to investigate structural and physical properties of the 1/1 approximant of the icosahedral Al-Cu-Fe quasicrystal. Particular local structural arrangements of atoms, referred to here as clusters, have been analyzed with respect to their properties within the crystal structure. Artificial strain and cracks have been introduced to probe their ...
On the basis of ab initio calculations employing density functional theory (DFT) we investigate half metallic ferromagnetism in zinc-blende and wurtzite compounds composed of group I/II metals as cations and group V elements as anions. We find that the formation of ferromagentic order requires large cell volumes, high ionicity and a slight hybridization of ...
A fundamental understanding of radiation damage effects in solids is of great importance in assisting the development of structural materials with improved mechanical properties for nuclear energy applications. In this presentation, we discuss our recent theoretical investigation on the magnetic structure evolution in bulk Fe after an energetic particle has disturbed the ...
Using ab-initio calculations, we study the properties of the multiferroic BiFeO3 compounds in the perfect cubic perovskite lattice structure. We show that the appearance of magnetism is energetically favorable. Except the ferromagnetic structure, there are three possible antiferromagnetic arrangements, which are close in energy, and for large values of the ...
This talk presents the result of an ab-initio study of Ruddlesden-Popper(RP) phases for Srn+1TinO3n+1(n = 1, 2, 3, ?) compounds with the density functional theory(DFT). In particular, we present results for the relation between octahedral rotations and external strains. We find that rotational reconstructions are energetically favorable under nonzero ...
Ab-initio quantum mechanical calculations show that several percent potassium (K) can be alloyed into iron (Fe) at high pressure, suggesting that K may have been incorporated into the Earth's iron-rich core. We find that substitutional incorporation of K into the high-pressure polymorph of Fe, hexagonal close packed (hcp) $\\varepsilon$-Fe, is ...
An ab initio investigation of the Si(111)-(7�7) surface reconstruction is undertaken using the state of the art in massively parallel computation. Calculations of the total energy of an ~700 effective-atom supercell are performed to determine (1) the fully relaxed atomic geometry, (2) the scanning-tunneling-microscope images as a function of bias ...
We have found that a beryllium (Be) atom on nanostructured materials with H2 molecules generates a Kubas-like dihydrogen complex [Lee, Huang, Duan, and Ihm, Appl. Phys. Lett. 96, 143120 (2010)]. Here, we investigate the feasibility of Be-decorated fullerenes for hydrogen storage using ab initio calculations. We find that the aggregation of Be atoms on ...
Ab initio molecular orbital methods were applied to screening tests of the organometallic source materials suitable for the photo-assisted low-temperature growth of stoichiometric epitaxial films of group-III nitrides. The molecular properties of dimethylgalliumnitrene ((CH3)2GaN), dimethylaluminumnitrene ((CH3)2AIN), and dimethylboronnitrene ((CH3)2BN) ...
Ab initio molecular orbital theory was used to examine the hydrogenation of a B12N12 molecule. The 1,2 addition of the 4,6 bond is an energetically favorable adsorption site in one-hydrogen-molecule adsorption. We found that the averaged bind energy of hydrogen molecule is maximized in B12N12H12. The largest energy gaps of B12N12H12 ...
We have employed ab initio molecular dynamics to investigate the equilibrium geometries, energetics, and the nature of bonding in mixed Li-Sn clusters. Our studies reveal that a small percentage of Sn in Li-rich clusters introduces significant changes in the equilibrium geometries. It is also seen that the geometries of Sn-rich ...
We discuss a structure model for icosahedral AlPdMn that is based on ab initio simulation studies. The main structural features of this model have gradually been refined after studying a series of crystalline reference structures and after optimizing a suitable crystalline approximant for i-AlPdMn. We also report on the energetics of ...
Ab initio quantum mechanical calculations on small hydration complexes involving the nitrate anion are reported. The self-consistent field method with accurate basis sets has been applied to compute completely optimized equilibrium geometries, vibrational frequencies, thermochemical parameters, and stable site labilities of complexes involving 1, 2, and 3 ...
Using ab initio methods, we theoretically investigate the adsorption of one and two Pt dimers on Cu(001). Treating the interaction of adsorbates on surfaces as a local phenomenon, a representation of the substrate by a large cluster of at least 62 Cu atoms allows one to treat the electronic structures of both systems, that is, the adsorbate and the ...
We have studied the energetics and charge tranfer of the (10,0) and (6,6) single walled carbon nanotubes with various defects such as monovacancy and Stone-Wales defect and their interaction with the Hydrogen Sulphide gas molecule using Ab Initio based computational method to design Single Walled Carbon Nanotube based gas sensor . We ...
We report on the determination of a high quality ab initiu potential energy surface (PES) and dipole
The robust prediction of accurate physical properties for molecular solids from first-principles calculations continues to present a significant challenge across a wide variety of scientific disciplines. Comparison between computed and experimental values for physical properties derived from differences between states is often promising (such as bulk modulus), however the result is disappointing ...
An outstanding problem in the computer-based microscopic description of Group IV materials, is the need for an accurate transferable model of the energetic and electronic properties of semiconductor structures. The three complementary approaches have been the ab-initio method including Car-Parinello simulations, the classical molecular dynamics method, and ...
In this project we have proposed several mechanisms for radiation damage and recently radiation protection to DNA and its constituents, and have detailed a series of experiments utilizing electron spin resonance spectroscopy, HPLC, GC-mass spectroscopy and ab initio molecular orbital calculations to test the proposed mechanisms. In this years work we have ...
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 ...
Ab initio molecular orbital calculations have been performed in this study to determine the stability of five deoxyribose centered radicals embedded in a short DNA segment. The effect of phosphate groups on the sugar radical conformation, energetics, and electronic properties are evaluated through a comparison of models with and ...
We analyze structure of superdislocation in the context of the anomalous yield stress behaviour using generalized stacking fault (GSF) energies for L12 Ni_3Al, Ni_3Ge and Fe_3Ge intermetallics calculated within the local spin-density approximation, using a variant of the full-potential linear muffin-tin orbital (FLMTO) method. One feature of calculated GSF stands out in particular: there is no ...
