Collect. Czech. Chem. Commun. 1988, 53, 2073-2081

Applications of the MBPT in the localized representation the behaviour of the localization terms

Ede Kapuya,b, Zoltán Csépesb, Ferencz Barthaa, Ferencz Bogára and Cornelia Kozmutzab

a Department of Theoretical Physics, József Attila University, H-6720 Szeged, Hungary
b Quantum Theory Group, Physics Institute, Technical University of Budapest, H-1421 Budapest, Hungary


The behaviour of the localization corrections of the MBPT is investigated. It is shown that calculating the third and fourth order localization corrections we obtain sufficiently accurate results to the second order correlation energy both for cyclic polyenes and for saturated hydrocarbons. The evaluation of the localization diagrams does not require significant extra computer time. The extra computer time can be recovered if small non-local effects will be neglected.