The theoretical description of ionic states observed by high energy photoelectron spectroscopy

Abstract

Core ionization potentials of some simple first-row molecules are calculated from ab initio molecular wavefunctions in a number of approximations. Valence orbital relaxation is included by performing configuration interaction calculations utilizing the virtual orbitals of the neutral species. By this method, with the use of an atomic orbital basis of double zeta quality or better, very good agreement with experimental core binding energies is obtained. The origin of the satellite peaks observed in high-energy photoelectron spectra is discussed with the aid of these calculations.