Dual-Space Operator Technique to Build Symmetry-Adapted Wave Functions. II. Occupation-Branching-Number Representation for Molecules with Abelian Symmetry Groups

Abstract

A treatment of molecular excited states in the second-quantization formalism, using the dual-space operator technique, is given. The open-shell configurations give degenerate multiplets which are easily described in what we call the occupation-branching-number representation. Equivalent monoelectronic and bielectronic operators are defined and a diagrammatic technique is developed. The method is at present restricted to molecules with Abelian symmetry groups. A linked-cluster theorem is finally proved.