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Diagrammatic formulation of the second‐order many‐body multipartitioning perturbation theory
Author(s) -
Zaitsevskii Andréi,
Cimiraglia Renzo
Publication year - 1999
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(1999)73:5<395::aid-qua2>3.0.co;2-t
Subject(s) - diagrammatic reasoning , hamiltonian (control theory) , electronic correlation , perturbation (astronomy) , perturbation theory (quantum mechanics) , electron , physics , quantum mechanics , statistical physics , theoretical physics , mathematical physics , computational chemistry , mathematics , chemistry , computer science , mathematical optimization , programming language
The second‐order multireference perturbation theory employing multiple partitioning of the many‐electron Hamiltonian into a zero‐order part and a perturbation is formulated in terms of many‐body diagrams. The essential difference from the standard diagrammatic technique of Hose and Kaldor concerns the rules of evaluation of energy denominators which take into account the dependence of the Hamiltonian partitioning on the bra and ket determinantal vectors of a given matrix element, as well as the presence of several two‐particle terms in zero‐order operators. The novel formulation naturally gives rise to a “sum‐over‐orbital” procedure of correlation calculations on molecular electronic states, particularly efficient in treating the problems with large number of correlated electrons and extensive one‐electron bases. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 73: 395–401, 1999