Partitioning of the Hamiltonian operator in the lie algebra formalism. Applications to the generalized brillouin theorem and the open‐shell Hartree‐Fock approximation

Abstract

AbstractThe Born‐Oppenheimer spin‐conserving Hamiltonian operator expressed in terms of the Lie algebra generators is partitioned according to the number of connected lines in the corresponding graphical representation. A simple derivation of some basic relations with the generalized Brillouin theorem, HF approach, and random phase approximation is presented.