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Energy density analysis for second‐order Møller‐Plesset perturbation theory and coupled‐cluster theory with singles and doubles: Application to C 2 H 4 CH 4 complexes
Author(s) -
Imamura Yutaka,
Nakai Hiromi
Publication year - 2008
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.20913
Subject(s) - coupled cluster , møller–plesset perturbation theory , perturbation theory (quantum mechanics) , electronic correlation , cluster (spacecraft) , density functional theory , physics , atomic physics , chemistry , quantum mechanics , electron , molecule , computer science , programming language
Grid‐based energy density analysis (EDA), in which numerical integration is performed for two‐electron integrals by the pseudospectral method (Imamura et al., J. Chem. Phys. 2007, 126, 034103), is extended to correlated methods: second‐order Møller‐Plesset (MP2) perturbation and coupled‐cluster singles and doubles (CCSD). Using EDA for MP2 and CCSD, we estimate atomic correlation energy differences and correlation energy density difference maps for C 2 H 4 CH 4 complexes. The analyses confirm that polarization and diffuse functions essentially contribute to the descriptions of weak interaction around the nuclei and in the area between C 2 H 4 and CH 4 , respectively. © 2008 Wiley Periodicals, Inc. J Comput Chem 29: 1555–1563, 2008