... Title : AB Initio Quantum Chemical Investigations of Solubilities in Supercritical Solutions. Descriptive Note : Conference Paper,. ...
DTIC Science & Technology
... This study involves: Ab-initio crystal orbitals and polymer orbitals; Ab-initio coupled cluster program; Ab-initio quantum chemical calculations and ...
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
... Abstract : Ab-initio quantum chemical investigations of the mechanism of cationic polymerization; Development, implementation testing of ...
... Abstract : Contents: Ab-initio quantum chemical investigations of the mechanism of cationic polymerization; Development of theoretical procedures ...
Ab initio quantum chemical techniques are used to investigate covalently-bonded and hydrogen-bonded species that may be important intermediates in the reaction of hydroxyl and hydroperoxyl radicals. Stable structures of both types are identified. Basis se...
National Technical Information Service (NTIS)
The adsorption energies of methane and ethane in zeolites are investigated with ab initio molecular orbital theory and density functional theory. In this work we have used zeolite cluster models containing two, three, and five tetrahedral (Si, Al) atoms a...
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...
An ab initio centroid molecular dynamics (CMD) method is developed by combining the CMD method with the ab initio molecular orbital method. The ab initio CMD method is applied to vibrational dynamics of diatomic molecules, H2 and HF. For the H2 molecule, the temperature ...
NASA Astrophysics Data System (ADS)
Structural and thermal properties of small lithium clusters are studied using ab initio-based Monte Carlo simulations. The ab initio scheme uses a Hartree-Fock/density functional treatment of the electronic structure combined with a jump-walking Monte Car...
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;...
"An ab initio. Investigation of Possible. Intermediates in the Reaction of the. Hydroxyl ... "A Quantum. Chemical. Investigation of the. 2A 1 Excited ...
... Andrew Ichimura Ph. ... AS Ichimura, AR Matlin, PM Lahti, "An Ab Initio Study of Methano and Ethano Bridged Derivatives of Oxyallyl.", J. Am. Chem. ...
... used successfully the strategy for ab-initio MRD-CI ... polymerization; Energetic polymers; Oxetanes; Quantum chemical calculations; Configuration ...
... Abstract : In the research on part I of this project we are carrying out ab-initio quantum chemical calculations and generating electrostatic molecular ...
... Stabilities of Low-Coordinated pi-Bonded Phosphorus Systems. An ab initio Quantum Chemical Investigation. p9 and 10. ...
Jun 16, 2011 ... The reactivity of a wide variety of phenolic compounds with formaldehyde was investigated using semi-empirical and ab initio computational ...
Treesearch
There has been only a limited amount of experimental investigation of the photoabsorption and photoionization processes of the OH radical. In this paper, we present ab initio calculations of photoionization cross sections and photoelectron angular distrib...
... As an initial step in investigating the possibility that zeolite catalysts might help to circumvent these problems, we have carried out ab initio ...
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...
... cysteinyl form has been further supported by nuclear magnetic resonance and Raman spectra of the 390 nm intermediate (9,10). The ... ...
NBII National Biological Information Infrastructure
dihydromatricaria acid,9 oenanthotoxin,10 cicutoxin,11 and falcarinol12 have been exploited by native Americans
E-print Network
... Andrew Ichimura Ph. ... AS Ichimura, A. R. Matlin, PM Lahti, "An Ab Initio Study of Methano and Ethano Bridged Derivatives of Oxyallyl.", J. Am. Chem. ...
... Energetic polymers, Oxetanes, Quantum Chemical calculations, Configuration ... MRD/CI), Energetic compounds, Ab-initio potential functions, Crystal ...
... We have also calculated further ab-initio atom class-atom class potential functions. Keywords: Quantum chemical electrostatic molecular potential ...
... atoms and molecule in order to avoid possible loss of molecules during photoassociation. The result of our investigation is shown in Fig. ...
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 ...
The interaction of CO{sub 2} and water is investigated by a combination of ab initio and SOLDRI-MM2 techniques. Ab initio results at levels of theory as high as MP2/6-311+G**//6-31G** are found to be in reasonable agreement with experiment. The R.{theta} potential energy surfaces generated for ...
Energy Citations Database
In this work, we present a study on water acetonitrile (AN) mixtures by molecular dynamics ab initio and X-ray diffraction techniques. Comparison of the experimental total G(r) functions of the mixtures with the results of molecular dynamics simulation shows an overall good agreement. The properties of hydrogen bonded clusters (water clusters, and water AN ...
... 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. ...
) to applied external force. We first investigate the mechanical response using an ab initio molecular dynamics where the reaction path depends on the strength and nature of the applied force. We first investigate the response of CB under applied forces using steered molecular dynamics8 (SMD) combined with ...
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-...
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...
The structures of Al sub 2 F sub 7- and Al sub 2 Cl sub 7- have been investigated using ab initio molecular orbital theory including the effects of polarization functions in the basis sets. The Al sub 2 F sub 7- ion has a linear or nearly linear Al-F-Al b...
The methodology of nonempirical ab initio quantum mechanical calculations is reviewed as applied to the field of mineral surface chemistry and water-rock geochemical kinetics. The ab initio treatment of adsorption deals with the covalent forces between surface atoms and molecules either in solution or in the gas ...
In this review we present the techniques of ab initio molecular dynamics simulation improved to its current stage where the analysis of existing processes and the prediction of further chemical features and real-world processes are feasible. For this reason we describe the relevant developments in ab initio ...
PubMed
We present results for the static and dynamic structural properties of undercooled liquid Si, at several temperatures between 1550 K and 1100 K, obtained through orbital-free ab-initio molecular dynamics simulations. The local bond angle distributions show a modest increase in the tetrahedral order upon decreasing the temperature. We also analyze the variation of several ...
... Title : AB Initio Study of the Electronic Magnetic Circular Dichroism ... functions are determined using as initio quantum chemical techniques including ...
Reevaluating electron-phonon coupling strengths: Indium as a test case for ab initio and many Using indium as a test case, we investigate the accuracy of the electron-phonon coupling calculated, since for indium we find that can only be given to within approximately 10%. Indium is an ideal
Techniques for applying ab-initio calculations to the analysis of atomic spectra are investigated, along with the relationship between the semi-empirical and ab-initio forms of Slater-Condon theory. Slater-Condon theory is reviewed with a focus on the ess...
The authors have calculated the band structures of organic conductors TTF-TCNQ and {beta}-(BEDT-TTF){sub 2}I{sub 3} using the ab initio plane-wave pseudopotential method within the local-density approximation (LDA). The Fermi-surface shape and the origin of bands near the Fermi level are investigated for each compound.
Ab initio methods are used to study the formation of hydrogen-bonded complexes of cis-1,2-diazene with trans-1,2-diazene, cis-1,2-diazene, and ethylene. These reactions have negligible activation enthalpies when the effects of electron correlation are included. Calculated and experimental free energies of activation are mostly entropic and in good ...
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. Along with these ...
Based on ab initio pseudopotential calculations, the results of investigations of the lattice dynamics of silver halides AgHal (Hal = Cl, Br, I) are presented. Equilibrium lattice parameters, phonon spectra, frequency densities and effective atomic-charge values are obtained for all types of crystals under study.
In this work, the structure of symmetric N2O3 was investigated using ab initio methods. Bond lengths and bond angles were determined using the 6-31 G* and the 6-311 G* basis sets using both SCF and MP2 theory. At the highest level of theory considered in ...
Ab initio calculations were performed to investigate reaction mechanisms for formation and decomposition of the six-membered ring C3N3H3, known as sym-triazine. MP2 geometry optimizations with QCISD(T) energy refinements for critical points on the potenti...
The electron transfer (ET) properties of 10- and 12-vertex carboranes are investigated by the ab initio Hartree-Fock method within the Marcus-Hush (MH) two-state model and the Koopman theorem (KT) approach. The calculated value of the ET coupling matrix e...
The use of ab initio molecular orbital calculations to aid in the characterization, i.e., structures and energies, of metal halide complexes present in high temperature salt vapors has been investigated. Standard LCAO-SCF methods were used and calculation...
The influence of changes in the contracted Gaussian basis set used for ab initio calculations of nuclear magnetic resonance (NMR) phosphorous chemical shift anisotropy (CSA) tensors was investigated. The isotropic chemical shift and chemical shift anisotr...
We present a theoretical investigation of the electronic structure of an InAs monomolecular plane inserted in bulk GaAs. Our calculations are based on the ab initio self-consistent pseudopotential method. Both electrons and holes are found to be strongly ...
and O�H bond length for a simple water molecule and for water in contact with NaCl surfaces. The resultsAB INITIO MOLECULAR�DYNAMICS SIMULATIONS OF ADSORPTION OF DYE MOLECULES AT SURFACES M. SUGIHARA, H molecules on the NaCl(100) surface. The investigations concentrate on the flat dye molecules trimethin, [C
Due to recent advances in methods and computers, the accuracy of ab calculations has reached a point
NASA Technical Reports Server (NTRS)
A theoretical research investigation of materials that are potential additives for solid hydrogen rocket fuels is investigated. The ab initio calculations show that mixed clusters of boron and lithium prefer to have an electronegative boron atom at the mi...
We present ab initio investigation of the electronic structure and magnetic properties of uranium monochal-cogenides: US, USe, UTe. The calculations were performed by using the recently developed LDA+ U+SO method in which both Coulomb and spin-orbit interactions have been taken into account in rotationally invariant form. We discuss ...
Theoretically determined frequencies and absorption intensities are reported for the vibrational spectrum of the covalent HOOOH and hydrogen bonded HO---HOO intermediates that may form in the reaction of the hydroxyl and hydroperoxyl radicals. Basis sets ...
The unimolecular dissociation dynamics of disilane are investigated using classical trajectory methods with a global potential-energy surface fitted to the available experimental data and the results of various ab initio calculations. The potential surfac...
The dynamics of the formation and dissociation of Si3 complexes in atom-dimer collisions have been investigated using quasiclassical trajectories on a potential-energy surface that is a global fit to the available experimental data and ab initio CI and MP...
The structure of atomic clusters is investigated using methods of ab initio quantum chemistry in conjunction with scanning tunneling microscopy (STM). Gold sols are imaged via STM and their sizes characterized. Atomic resolution reveals facets, steps, and...
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 research project involves an investigation of the interaction of carbon dioxide (CO2) with selected ionic liquids (ILs). Raman spectroscopy and first principle quantum mechanical calculations were performed on selected IL solvents in contact with CO2...
LDA + DMFT is a novel computational technique for ab initio investigations of real materials with strongly correlated electrons, such as transition metals and their oxides. It combines the strength of conventional band structure theory in the local densit...
Group of Young Researchers 'Quantum Chemistry' (Dr. M. Dolg) The group of young researchers 'Quantum Chemistry' works on quantitative ab initio electronic structure calculations for properties of relativity and electron correlation are investigated and interpreted. A major area of research
... positions signifi- F cantly affects the ab initio quantum chemical calculations or DDF = gk(R) O = (1/ FN,j)Nk(R)J I/d V, the PIXEL ...
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...
The requirements for very accurate ab initio quantum chemical prediction of dissociation energies are examined using a detailed investigation of the nitrogen molecule. Although agreement with experiment to within 1 kcal/mol is not achieved even with the m...
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...
. [26] M.I. Zeifman, B.J. Garrison, L.V. Zhigilei, J. Appl. Phys. 92 (2002) 2181. [27] H. Mizuseki, Y
The catalytic properties of cobalt oxide (Co0) were investigated theoretically. The interactions of atomic hydrogen with small clusters of atoms, representing cobalt oxide surfaces, were calculated using the ab initio Unrestricted Hartree-Fock (UHF) metho...
The nature of the bonding between halogen atoms (F, CI and Br) and the Ag (111) surface has been investigated by analyzing ab initio Hartree- Fock wave functions for cluster models of the Ag surface and a halogen atom. Using a variety of criteria, we conc...
Forty two scientific articles detailing the results of this research are abstracted and interrelated. Nine papers deal with the optical properties of solids including; Ab Initio Calculation of Crystal Tensor, Light Scattering, Morphic Effects, Group Theor...
We discuss a recent investigation of adatom behavior on the AISb(001) surface using first-principles electronic structure methods based on the density functional theory. For Al and Sb adatoms, we find a number of novel adatom structures that differ dramat...
This report results from a contract tasking Institute of Theoretical Physics and Astronomy as follows: The contractor will investigate quantum mechanical design of light-driven, single supermolecular logically-controlled machines and molecular computing d...
The objective of this work is to use in silico methods such as ab initio quantum and classical force-field methods to explore and develop an understanding for the enantioselective metabolism rates experimentally observed in the triazole fungicide bromuconazole. This directed stud...
EPA Science Inventory
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
... AB-INITIO SIMULATION OF a/2110> ... 4. TITLE AND SUBTITLE AB-INITIO SIMULATION OF a/2110> SCREW DISLOCATIONS γ-TiAl 5c. ...
... ADP012740 TITLE: Ab Initio Study on Spin Polarization of III-V Compound Tips ... Ab initio study on spin polarization of III-V compound tips ...
Ab initio electronic structure methods can supplement CALPHAD in two major ways for subsequent applications to stability in complex alloys. The first one is rather immediate and concerns the direct input of ab initio energetics in CALPHAD databases. The o...
...with this part. The certificate shall be void ab initio for those vehicles causing the...issued, and the certificate may be deemed void ab initio. (C) The manufacturer...with this part. The certificate shall be void ab initio for those vehicles causing...
Code of Federal Regulations, 2010
We present ab initio density functional investigations of the atomic and electronic structure of gallium nitride nanodots and nanowires. With increasing diameter, the average Ga-N bond length in the nanostructures increases, as does the relative stability (heat of formation), approaching the values for bulk GaN. As the diameter ...
Essential oils that contain large concentrations of germacrene D are typically accompanied by cadinane sesquiterpenoids. The acid-catalyzed cyclization of germacrene D to give cadinane and selinane sesquiterpenes has been computationally investigated using both density functional (B3LYP/6-31G*) and post Hartree-Fock (MP2/6-31G* *) ...
PubMed Central
In this article, we investigate the dependence of interatomic Coulombic decay widths on the symmetry of the decaying state. In this type of decay, excited, ionized, and doubly ionized states of an atom or molecule can efficiently relax by ionizing their environment. We concentrate on an atom A and a neighboring atom B and consider such excited, ionized, or doubly ionized ...
The nature of intermolecular interactions between aromatic amino acid residues has been investigated by a combination of molecular dynamics and ab initio methods. The potential energy surface of various interacting pairs, including tryptophan, phenilalanine, and tyrosine, was scanned for determining all the relevant local minima by a ...
Realistic electronic-structure calculations for correlated Mott insulators are notoriously difficult. Here we present an ab initio multiconfiguration scheme that adequately describes strong correlation effects involving Cu 3d and O 2p electrons in layered cuprates. In particular, the O 2p states giving rise to the Zhang-Rice band are explicitly considered. ...
We present a combined computational and experimental study on structural and electric properties of recently synthesized heteroaromatic dyes and their simple aggregates. Ab initio and density functional theory calculations are carried out to investigate ground state and excited state properties along with their modulation induced by ...
The dimerization of formamide (FMA) has been investigated by matrix isolation spectroscopy, static ab initio calculations, and ab initio molecular dynamics (AIMD) simulations. Comparison of the experimental matrix IR spectra with the ab initio ...
The infrared spectrum of methyl tert-butyl ether (MTBE) in liquid water has been studied using both FTIR absorption and FTIR-ATR spectroscopy in conjunction with ab initio calculations. Compared to the liquid MTBE IR spectrum, the C-O and C-C stretching vibrational frequencies of MTBE in water are found to shift to the red and blue by up to 26 and 9 cm ...
Recent progress in the ab-initio molecular dynamics method and the power of parallel computing, allow the detailed study of complex chemical reaction of great industrial relevance. We illustrate this unprecedented capability by investigating the second generation Ziegler-Natta catalytic process. In this inhomogeneous catalyst, a polymerization reaction is ...
We present the result of ab initio modeling of the Ge(111)-(2 � 1) surface electronic structure in the presence of donor doping atom at certain position in the surface bilayer of (2 � 1) reconstruction. We briefly compare these results with the data of experimental low temperature STM investigations. Ab ...
Cubic zirconia exhibits a soft phonon mode (X2-) which becomes dynamically unstable at low temperatures. Previous ab initio investigations into the temperature-induced stabilization of the soft mode treated it as an independent anharmonic oscillator. Calculations presented here, using the self-consistent ab ...
An ab initio density functional theory-based study of the electronic band structure, the elastic, electric, elastoelectric, and linear and nonlinear optical properties of the new ion conductor LiB6O9F, has been performed. The computed band structure reveals a wide direct band gap. The coefficients of the second order nonlinear susceptibility ?(2) were ...
In this paper, we summarize some results of our ab initio simulations aimed at investigating the mechanism of the NC-AFM image contrast on semiconductor and metallic surfaces. We start with an introduction into the basic ideas behind the ab initio simulation process of the NC-AFM experimental ...
Point defects in Fe and dilute FeCu alloys are investigated by ab initio calculations based on density functional theory. The relaxed vacancy and interstitial and substitutional Cu atom formation energies are determined as well as some migration energies. The binding energies of various Cu containing defects believed to play an ...
Structural and thermal properties of small lithium clusters are studied using ab initio-based Monte Carlo simulations. The ab initio scheme uses a Hartree-Fock/density functional treatment of the electronic structure combined with a jump-walking Monte Carlo sampling of nuclear configurations. Structural forms of ...
... ADP023770. Title : ab-Initio Molecular Dynamics Simulations of Molten Ni-Based Superalloys. Descriptive Note : Conference paper. ...
... Title : Ab-Initio Molecular Dynamics Simulations of Molten Ni-Based Superalloys. Descriptive Note : Conference paper (preprint). ...
... 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. ...
... Accession Number : ADA270577. Title : Ab Initio Potential Energy Surface for the H + OCS Reaction. Descriptive Note : Final rept. ...
... Ab initio direct trajectory simulation on hydrogen atom transfer in 7-azaindole in the electronic excited state with assist of water molecules ...
