Self-energies for the particle-hole propagator from Feynman-Dyson equations

BOCHICCHIO, ROBERTO R.; FERRARO, MARTA B.; GRINBERG, HORACIO; CAVASOTTO, CLAUDIO NORBERTO

JOURNAL OF MOLECULAR STRUCTURE THEOCHEM

ELSEVIER SCIENCE BV

Año: 1995 vol. 335 p. 1 - 9

0166-1280

Correlation-relaxation corrections to electronic transition energies are obtained through the self-energy fields for the particle-hole propagator. These objects are generated from Feynman-Dyson like equations within the scenario of the superoperator algebra. A Hartree-Fock reference state and a partition of the operator space along with a particle conserving manifold are used to recast the lower order perturbative expressions for the self-energies. Correlated states are used to make explicit the appearance of higher order correction terms to the self-energy. It is explicitly shown that the present scheme leads to a proper classification of the order of the contribution from both the intrinsic interaction operator and the improved reference state.