Selfhyphen;Consistent Polarization Propagator Approximation as a Modified Random Phase Method

摘要

A formal scheme is developed for finding the particlehyphen;hole propagator by means of a selfhyphen;consistent decoupling procedure analogous to the Hartreehyphen;Fock decoupling for the electron propagator. The selfhyphen;consistency comes from a contour integration of the Fourier transform of the propagator, utilizing a method introduced by Coulson. The method yields oscillator strengths and excitation energies, as well as the twohyphen;particle density matrix, which allows any onehyphen; or twohyphen;particle operator expectation value to be evaluated. The stability of the scheme is discussed, and comparisons with other, related, approximations are made.