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Density functional energy decomposition into one- and two-atom contributions

The present work provides a generalization of Mayer’s energy decomposition for the density-functional theory (DFT) case. It is shown that one- and two-atom Hartree-Fock energy components in Mayer’s approach can be represented as an action of a one-atom potential VA on a one-atom density ρ A or ρ B. To treat the exchange-correlation term in the DFT energy expression in a similar way, the exchange-correlation energy density per electron is expanded into a linear combination of basis functions. Calculations carried out for a number of density functionals demonstrate that the DFT and Hartree-Fock two-atom energies agree to a reasonable extent with each other. The two-atom energies for strong covalent bonds are within the range of typical bond dissociation energies and are therefore a convenient computational tool for assessment of individual bond strength in polyatomic molecules. For nonspecific nonbonding interactions, the two-atom energies are low. They can be either repulsive or slightly attractive, but the DFT results more frequently yield small attractive values compared to the Hartree-Fock case. The hydrogen bond in the water dimer is calculated to be between the strong covalent and nonbonding interactions on the energy scale

© Journal of Chemical Physics, 2005, vol. 122, núm. 24, p. 1-13

American Institute of Physics

Author: Vyboishchikov, Sergei F.
Salvador Sedano, Pedro
Duran i Portas, Miquel
Date: 2005
Abstract: The present work provides a generalization of Mayer’s energy decomposition for the density-functional theory (DFT) case. It is shown that one- and two-atom Hartree-Fock energy components in Mayer’s approach can be represented as an action of a one-atom potential VA on a one-atom density ρ A or ρ B. To treat the exchange-correlation term in the DFT energy expression in a similar way, the exchange-correlation energy density per electron is expanded into a linear combination of basis functions. Calculations carried out for a number of density functionals demonstrate that the DFT and Hartree-Fock two-atom energies agree to a reasonable extent with each other. The two-atom energies for strong covalent bonds are within the range of typical bond dissociation energies and are therefore a convenient computational tool for assessment of individual bond strength in polyatomic molecules. For nonspecific nonbonding interactions, the two-atom energies are low. They can be either repulsive or slightly attractive, but the DFT results more frequently yield small attractive values compared to the Hartree-Fock case. The hydrogen bond in the water dimer is calculated to be between the strong covalent and nonbonding interactions on the energy scale
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Citation: Vyboishchikov, S.F., Salvador, P., i Duran, M. (2005). Density functional energy decomposition into one- and two-atom contributions. Journal of Chemical Physics, 122, 24, 244110. Recuperat 29 març 2011, a http://link.aip.org/link/doi/10.1063/1.1935511
ISSN: 1089-7690 (versió paper)
0021-9606 (versió electrònica)
Document access: http://hdl.handle.net/10256/3319
Language: eng
Publisher: American Institute of Physics
Collection: Reproducció digital del document publicat a: http://dx.doi.org/10.1063/1.1935511
Articles publicats (D-Q)
Is part of: © Journal of Chemical Physics, 2005, vol. 122, núm. 24, p. 1-13
Rights: Tots els drets reservats
Subject: Compostos organometàl·lics
Descomposició, Mètode de
Enllaços d’hidrogen
Enllaços químics
Funcional de densitat, Teoria del
Chemical bonds
Density functionals
Decomposition method
Hydrogen bonding
Organometallic compounds
Title: Density functional energy decomposition into one- and two-atom contributions
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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