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Differences between ab initio and density functional electron densities
Author(s) -
OrtizHenarejos Ester,
SanFabián Emilio
Publication year - 1997
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/(sici)1097-461x(1997)61:2<245::aid-qua6>3.0.co;2-w
Subject(s) - electronic correlation , wave function , electron , ab initio , chemistry , electron density , atomic physics , molecular physics , physics , quantum mechanics , organic chemistry
We analyzed the energy contributions and the spatial distribution differences of several electron densities of atoms and small molecules. The results show the insensitivity of local spin density correlation functionals in respect to differences in the electron densities. On the other hand, significant changes in one‐electron and two‐electron energy contributions are observed, although both compensate each other. The projection of the differences between these electron densities, referred to as the Hartree‐Fock density, shows a qualitative resemblance between multideterminantal and Kohn‐Sham wavefunctions. Finally, a comparative analysis of the optimized conformational parameters obtained using several methods shows that the inclusion of the correlation energy in SCF or in post‐SCF procedures gives similar results and that the exchange potential is more important than is the correlation potential to improve these conformational parameters. © 1997 John Wiley & Sons, Inc.