Intramonomer correlation contributions to first-order exchange nonadditivity in trimers

Citation
Pes. Wormer et al., Intramonomer correlation contributions to first-order exchange nonadditivity in trimers, J CHEM PHYS, 112(7), 2000, pp. 3159-3169
Citations number
36
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF CHEMICAL PHYSICS
ISSN journal
00219606 → ACNP
Volume
112
Issue
7
Year of publication
2000
Pages
3159 - 3169
Database
ISI
SICI code
0021-9606(20000215)112:7<3159:ICCTFE>2.0.ZU;2-E
Abstract
An expression for the nonadditive first-order exchange contribution in term s of the one- and two-particle density matrices of the isolated monomers is given. This formula is used to derive the intramonomer correlation contrib ution to the first-order exchange nonadditivity with the density matrices o f the isolated monomers computed at the second-order Moller-Plesset level. As an illustrative example of the theory the trimer Ar 2-HF is considered. It is shown that the correlation contribution is far from negligible, not o nly in relation to the corresponding first-order uncorrelated exchange, but also in comparison to the other three-body terms. Moreover, it is fairly a nisotropic, so that it cannot be neglected in accurate calculations of nona dditive effects. (C) 2000 American Institute of Physics. [S0021-9606(00)301 06-4].