We have formulated a polarization propagator approach which yields excitation energies, transition moments, and dynamic polarizabilities which are consistent through second order in the electronic repulsion. Certain terms are proven to be missing in our previous second order calculations of transition moments and dynamic polarizabilities and in the equation-of-motion calculations of the same quantities. Numerical calculations on carbon monoxide are performed. The calculations show that the major difference between the polarizability (and some transition moments) in the RPA and in the second order polarization propagator approximation is due to these terms. The total effect of all correction terms has been to improve considerably the agreement between theoretical and experimental estimates of the excitation properties for carbon monoxide.

No abstract

We present the first application of the coordinate rotation method, within the time-dependent Hartree-Fock framework, to calculation of positioas and widths of metastable excited states. The method is briefly outlined and results of its application to ' P excited states of Li-are given. Comparison of our results to those obtained using electron scattering methods by other workers is also made.