Título:
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Density functional energy decomposition into one- and two-atom contributions
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Autor/a:
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Vyboishchikov, Sergei F.; Salvador Sedano, Pedro; Duran i Portas, Miquel
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Abstract:
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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 |
Fecha de creación:
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30-03-2011 |
Materia(s):
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-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 |
Derechos:
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Tots els drets reservats |
Tipo de documento:
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Artículo |
Editor:
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American Institute of Physics
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Compartir:
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