Self-Consistent Perturbation Theory. I. General Formulation and Some Applications

The self-consistent perturbation theory developed in an earlier paper is formulated more explicitly and applied to various types of perturbation: (i) one-element change of the one-electron Hamiltonian matrix (i.e., of Coulomb or resonance integral), (ii) uniform electric field, (iii) point charge near the system. The applications are to π-electron systems, where the results have considerable chemical interest.