On double vacancies in the core

Abstract

The energies needed to create different types of double core vacancies as well as the resulting redistribution of the valence electrons are analyzed in comparison with single core vacancies. Numerical results are presented for CH4 and in particular for the molecules C2H2, C2H4, and C2H6. A detailed perturbation theory analysis of the relaxation energies in terms of localized and delocalized molecular orbital pictures is presented. It is shown that the binding energies associated with double core vacancies where each of the two core holes is at a different atomic site sensitively probe the chemical environment of the atoms.