PATH-INTEGRALS SEMICLASSICAL QUANTIFICATION

We discuss hem a new formal way to evaluate the electronic correlation energy of a molecular system. We use the path integral formalism in t he regime of the molecular orbitals. The semiclassical approximation i n this procedure is an expansion of the effective action S(eff) around the classical closed orbits into generalized phase space keeping only the quadratic fluctuation. Thus, after some transformations, we apply to the final expression analogous conditions to the Bohr-Sommerfeld q uantification rules. (c) 1994 John Wiley & Sons, Inc.