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A multireference configuration interaction method based on the separated electron pair wave functions
Author(s) -
Ma Jing,
Li Shuhua,
Li Wei
Publication year - 2005
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.20319
Subject(s) - wave function , complete active space , atomic orbital , configuration interaction , chemistry , multireference configuration interaction , dissociation (chemistry) , atomic physics , computational chemistry , molecular orbital , electron , physics , quantum mechanics , molecule , excited state , organic chemistry
Abstract A multireference configurational interaction method based on the separated electron pair (SEP) wave functions, SEP‐CI approach, has been developed as an approximation to the traditional CASSCF method. It differs from the CASSCF method in that active orbitals are obtained from the SEP wave function without further optimization in the subsequent CI calculations, and the active space is automatically constructed according to the occupation coefficients of SEP natural orbitals. These features make the present SEP‐CI method computationally much less demanding than the CASSCF method. The applicability of the SEP‐CI method is illustrated with sample calculations on the insertion reaction of BeH 2 and dissociation energies of LiH, BH, FH, H 2 O, and N 2 . © 2005 Wiley Periodicals, Inc. J Comput Chem 27: 39–47, 2006