Due to recent advances in methods and computers, the accuracy of ab calculations has reached a point
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 o...
National Technical Information Service (NTIS)
... from federally funded research, testing and training ... agencies for Research Development Test and Evaluation ... Title : New AB Initio Based Density ...
DTIC Science & Technology
... Title : Structure of Perfluoromethanimine by Microwave, Infrared, and Raman Spectroscopy, Electron Diffraction, and ab Initio Methods,. ...
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
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 ...
NASA Astrophysics Data System (ADS)
... (U) DEVELOPMENT OF EFFECTIVE QUANTUM CHEMICAL METHOD FOR ... array of semiempirical approaches and ab initio calculations followed ...
the parameters for a polarizable force field from ab initio quantum-chemical calculations, and a rigorous method initio quantum- chemical calculations have become an increasingly impor- tant source of fitting dataParametrizing a polarizable force field from ab initio data. ...
E-print Network
In the second phase, a ultrafast semi-empirical ab initio method is ... High level quantum chemical calculations are then performed to further narrow down ...
NASA Website
... goals of this program have been to develop new, more effective methods for performing accurate ab initio electronic structure calculations and to ...
... Abstract : This report describes the development and application of ab initio quantum chemical methods that are especially relevant to the study of ...
Ab initio quantum chemistry methods are used to study the energetics of interactions of O atoms with
... atoms in fullerene and diamond nanocrystallite, respectively, are proposed and examined with ab-initio local density functional method for possible . ...
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 c...
Ab initio calculations of single and double differential cross sections for ionization by fast, charged particles within the framework of Born approximation are presented. In addition, a semiempirical method based on the asymptotic Bethe-Boron expansion i...
General procedures for computing alloy phase equilibria from ab initio electronic structure calculations are reviewed and applied to the Al-Li phase diagram. Free energies were calculated by the cluster variation method (CVM) in the tetrahedron approximat...
...from such establishment, become void ab initio if the device comprising such shipment...2) of this section shall become void ab initio with respect to the person who...or other media, the equipment, and the testing method or quality controls to be used...
Code of Federal Regulations, 2011
NIST Computational Chemistry Comparison and Benchmark Database (Web, free access)�� The NIST Computational Chemistry Comparison and Benchmark Database is a collection of experimental and ab initio thermochemical properties for a selected set of molecules. The goals are to provide a benchmark set of molecules for the evaluation of ...
National Institute of Standards and Technology Data Gateway
We present an algorithm for calculating the conformational thermodynamics of large, flexible molecules that combines ab initio electronic structure theory calculations with a torsional path integral Monte Carlo (TPIMC) simulation. The new algorithm overcomes the previous limitations of the TPIMC method by including the thermodynamic ...
SnO2: BULK AND SURFACE SIMULATIONS BY AN AB INITIO NUMERICAL LOCAL ORBITALS METHOD A.V. POSTNIKOVa structure of ideal bulk SnO2 is well studied by ab initio calculations (Peltzer y Blanc�a, Svane study of several SnO2 surfaces, com- paring their energies of formation, and started to look
A global search for possible LiF cluster structures is performed up to (LiF)(8). The method is based on simulated annealing, where all the energies are evaluated on the ab initio level. In addition, the threshold algorithm is employed to determine the energy barriers for the transitions among these structures, for the cluster (LiF)(4), ...
PubMed
We have studied structural and dynamical properties of Mg2Sn by employing an ab-initio pseudopotential method and a linear response scheme, within the generalised gradient approximation. The calculated lattice constant, bulk modulus and pressure derivative of bulk modulus are in agreement with previous ab-initio calculations and ...
Energy Citations Database
... known GAMESS suite of computer codes [2]. Accurate ab initio methods pro- ... to the systematic improvement of standard quantum-chemical methods ...
A initio quantum chemical methods are seeing increased application in a large variety of real-world problems including biomedical applications ranging from drug design to the understanding of environmental mutagens. The vast majority of these quantum chem...
... This study involves: Ab-initio crystal orbitals and polymer orbitals; Ab-initio coupled cluster program; Ab-initio quantum chemical calculations and ...
quantum chemical method rather than an ab initio one. Although the approximate nature of semiempirical results must be stressed, such methods are reliable ...
... substantial impact; these tools are now incorporated in many ab initio codes ... Most commonly used quantum chemical methods possess one or the ...
... 11. TITLE (Include Security Classification) Analytic Methods Using Computer Algebra with Slater-Type Orbitals for Problems in AB Initio Quantum ...
... Title : Analytic Methods Using Computer Algebra with Slater-Type Orbitals for Problems in AB Initio Quantum Chemistry and Molecular Physics. ...
A simple method is described to adjust a potential energy surface to improve agreement with experiment. An application is made to the ab initio HCO potential energy surface.(AIP)
The theory of trapping and diffusion of helium and hydrogen in metals is reviewed. The fundamental aspects of the behavior of these particles is emphasized and hence ab initio methods of calculation of interatomic potentials are described. In particular, ...
... goals of this program have been to develop new, more effective methods for perform in accurate ab initio electronic structure calculations and to ...
... Abstract : The results of ab initio calculations based on the density-functional method and using the norm-conserving pseudopotentials for the ...
respectively, are proposed and examined with ab-initio local density functional method for possible applications as single quantum bits (qubits) in ...
beyond the practical range of the standard ab-initio methods of quantum chemistry because of the large numbers of electrons involved. If one could ...
... Corporate Author : BATTELLE MEMORIAL INST RESEARCH TRIANGLE PARK NC. ... high level ab initio SCF and configuration interaction methods. ...
Research progress on an alternative method to ab initio variational and perturbative approaches for the electronic structure of molecules is described. Progress in the report year on the evaluation of (1) molecular properties, (2) energy derivatives with ...
... Abstract : Quantum chemical methods (ab initio, semiempirical, and Hartree-Fock) were used to calculate the energy of several phosphite ...
... crystal structures which are ordered superstructures of a parent disordered phase; a highly reliable statistical mechanical method (CVM) has now ...
... and many-body perturbation theory (MBPT) methods for the accurate inclusion of electron correlation in ab initio quantum chemical calculations of ...
... The interaction-induced dipole moment of the Ar-H2 van der Waals dimer was computed using ab initio quantum chemical methods in order to ...
(either ab initio methods or basis sets) for electronic structure calculations, and a graph theory procedure for identifying instantaneous molecular fragment identities...
Science.gov Websites
control of molecular dynamics; grid methods in the solution of time-dependent problems in quantum mechanics; ab initio calculation of potential energy surfaces and vibronic...
... Beta-(1-methyl-2-pyridinium) - alpha-cyano-4-styryldicyanomethanide was optimized using semi-empirical and ab initio quantum chemical methods ...
... Detailed analyses, including 6-31G' and MP2/6-31G* ab initio calculations, were performed for ... formed comparative quantum chemical calculations ...
... previous grant period have been to develop new, more effective methods for performing accurate ab initio electronic structure calculations and to ...
... the PRMD code - in Step 1- will be validated and further studied using ab initio methods to determine kinetic and thermodynamic properties of the ...
... solidification; Density; Nickel alloys; Liquids; Diffusion-liquid; ... erties of molten Ni-based alloys. The simulation method evolves ionic positions using ...
... More recently, extensive calculations on the nitrogen oxides were conducted employing the density functional method (ref 2) in conjunction with a ...
The CCSD(T) method, singles and doubles coupled-cluster theory plus a perturbational estimate of the
... Abstract : Electronic structure calculations using theoretical methods based on the linked-diagram theorem are reported for a series of dissociation ...
... Title : A Comparative Study of Nonlocal Density Functional Theory and ab initio Methods: The Potential Energy Surface of sym-Triazine Reactions. ...
Mar 1, 2011 ... respectively, are proposed and examined with ab-initio local density functional method for possible applications as single quantum bits ...
