SPONTANEOUS SYMMETRY-BREAKING AND ELECTRON CORRELATION

The Dyson equation and Green's function formalism map the problem of N electrons in the Born-Oppenheimer nuclear field into a one-electron S chrodinger equation problem in quantum chemistry. The mass operator co ntains the information about electron correlation, and the ground-stat e energy, electron affinity, and ionization energy of a molecular syst em. This pseudopotential approach is combined with the random-phase ap proximation (RPA) method to give a model with spontaneous symmetry bre aking, where the relevant features are incorporated in a transparent w ay. An effective potential is developed consisting of a Hartree-Fock s olution with auxiliary fields to probe for deformation instabilities. The model is then connected to a closely related perturbative propagat or approach and linked with the configuration interaction formalism. ( C) 1997 John Wiley & Sons, Inc.