Advances Topics in Theoretical Chemical Physics

0181837 - UFCH-W 20030281 RIV NL eng M - Monography Chapter
Wilson, S. - Hubač, I. - Mach, P. - Pittner, Jiří - Čársky, Petr
Brillouin-Wigner Expansions in Quantum Chemistry: Bloch-Like and Lippmann-Schwinger-Like Equations.
1-4020-1564-X. In: Advances Topics in Theoretical Chemical Physics. Dordrecht: Kluwer Academic, 2003 - (Maruani, J.; Lefebvre, R.; Brändas, E.), s. 71-117. Progress in Theoretical Chemistry and Physics., 12
R&D Projects: GA MŠMT OC D23.001; GA AV ČR IAA4040108
Institutional research plan: CEZ:AV0Z4040901
Keywords : ab initio calculations * multireference coupled cluster * Brillouin-Wigner expansions
Subject RIV: CF - Physical ; Theoretical Chemistry

Some recent progress on the application of Brillouin-Wigner expansions in quantum chemistry is reviewed. Brillouin-Wigner perturbation theory is used to obtained both a Bloch-type equation and a Lippmann-Schwinger-type equation in Brillouin-Wigner form. Both the single reference and the multireference formulation of the expansion are considered. The Bloch-like equation together with the Lippmann-Schwinger-like equation can be used to derive a Brillouin-Wigner coupled cluster (BWCC) expansion whilst the Lippmann-Schwinger-like equation can be used twice to cast the configuration interaction expansion in Brillouin-Wigner form (BWCI). By exploiting an identity relating the Brillouin-Wigner denominator to the Rayleigh-Schrödinger denominator, a posteriori corrections to the multireference Brillouin-Wigner coupled cluster theory and to the limited multireference configuration method are defined. A brief survey of applications is made.
Permanent Link: http://hdl.handle.net/11104/0078352