A Discussion on photoelectron spectroscopy - The role of autoionization in molecular photoelectron spectra

Abstract

The Fano-Mies theory of configuration interaction is applied to the photoionization of diatomic molecules, yielding an expression which gives the relative intensity of vibrational peaks in photoelectron spectra when one or more autoionizing states are in the vicinity of the excitation energy. In some cases the vibrational intensity distribution depends only on Franck-Condon factors connecting autoionizing and final states. Illustrative calculations for O2 show the transition from this limit to the limit of direct photoionization as the line profile index decreases.