Calculation of molecular ESCA spectra by the multiple-scattering-<i>X</i>α method

Abstract

The recently developed multiple-scattering method has been applied to the solution of the approximate SCF (Xα) equations. Through the concept of the transition state, it is possible with this method to estimate the ionization energies measured in electron spectroscopy (ESCA) experiments. Comparisons with experimental ionization energies for several small molecules (i.e., CF4, NH3, N2, CO, NO, CO2, N2O, C3O2) show in general, better agreement than semiempirical orbital energies and about the same as ab initio MO-LCAO-SCF orbital energies.