Change of molecular structure in the excited states: a (CNDO/2) hole-potential study on phosphin

Abstract

Molecular structure of phosphine in a number of excited electronic states is studied using the method of hole-potential within the basic framework of CNDO/2 theory. Effects of including 3d-functions of phosphorus in the basis set on computed molecular geometries, transition energies and inversion barriers in the excited states have been investigated. An attempt is made to rationalise qualitatively the structural changes in the excitedstate in terms of Walsh-type correlation diagram constructed with the eigenvalues of the Fock operator in theV N-1 potential model. A simple orbital model for predicting the nature of structural changes in the excited states is proposed.