Search results for "Potential energy functions"

showing 2 items of 2 documents

Method specific Cholesky decomposition : Coulomb and exchange energies

2008

We present a novel approach to the calculation of the Coulomb and exchange contributions to the total electronic energy in self consistent field and density functional theory. The numerical procedure is based on the Cholesky decomposition and involves decomposition of specific Hadamard product matrices that enter the energy expression. In this way, we determine an auxiliary basis and obtain a dramatic reduction in size as compared to the resolution of identity (RI) method. Although the auxiliary basis is determined from the energy expression, we have complete control of the errors in the gradient or Fock matrix. Another important advantage of this method specific Cholesky decomposition is t…

PhysicsPotential energy functionsBasis (linear algebra)General Physics and AstronomyMinimum degree algorithmUNESCO::FÍSICA::Química físicaPhysics and Astronomy (all)Computational chemistryFock matrixDensity functional theoryHadamard productApplied mathematicsSCF calculationsDensity functional theoryDensity functional theory ; Hadamard matrices ; Potential energy functions ; SCF calculationsHadamard matricesPhysical and Theoretical Chemistry:FÍSICA::Química física [UNESCO]ScalingCholesky decompositionSparse matrix
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Study of the benzene⋅N2 intermolecular potential-energy surface

2003

The intermolecular potential-energy surface pertaining to the interaction between benzene and N2 is investigated theoretically and experimentally. Accurate intermolecular interaction energies are evaluated for the benzene–N2 van der Waals complex using the coupled cluster singles and doubles including connected triples [CCSD(T)] method and the aug-cc-pVDZ basis set extended with a set of 3s3p2d1f1g midbond functions. After fitting the energies to an analytic function, the intermolecular Schrödinger equation is solved to yield energies, rotational constants, and Raman-scattering coefficients for the lowest intermolecular levels of several benzene–N2 isotopomers. Experimentally, intermolecula…

Potential Energy SurfacesCoupled Cluster CalculationsNitrogenBinding energyGeneral Physics and AstronomyPotential Energy Functionssymbols.namesakePhysics and Astronomy (all)IsomerismQuasimoleculesRotational IsomerismPhysics::Atomic and Molecular ClustersQuantum-mechanical explanation of intermolecular interactionsRotational StatesPhysical and Theoretical ChemistryPhysics::Chemical Physics:FÍSICA::Química física [UNESCO]Basis setSchrodinger EquationChemistryOrganic CompoundsIsotope EffectsIntermolecular forceStimulated Raman ScatteringUNESCO::FÍSICA::Química físicaCoupled clustersymbolsAtomic physicsvan der Waals forceOrganic Compounds ; Nitrogen ; Quasimolecules ; Potential Energy Surfaces ; Potential Energy Functions ; Coupled Cluster Calculations ; Rotational States ; Isomerism ; Isotope Effects ; Stimulated Raman Scattering ; Rotational Isomerism ; Schrodinger EquationRaman spectroscopyRaman scattering
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