Improvement of the effective nuclear charge model for diatomic molecules. VI

Abstract

The effective nuclear charge model previously proposed for predicting the valence force constants of polyatomic molecules is further developed to make the exact description of molecular vibrations. The effective intramolecular potential function assumed in such a model is somewhat improved for diatomic molecules, i.e., the correction term due to the delocalized valence electrons is expanded near equilibrium in the analytic form of an inverse power series of the internuclear distance. It is shown that the resulting potential is useful in estimating the anharmonic force constants as well as in describing the excited electronic states of diatomic molecules.