Model calculations for the C(K V V) and O(K V V) Auger transitions for CO on Ni(100)

Abstract

Model calculations of the core and valence electron binding energies and the two-hole final state Auger binding energies for the C(KVV) and O(KVV) transitions are performed for the Ni–CO system. The chosen atomic geometry is appropriate for a qualitative description of the CO–C(2×2)–Ni(100) structure. The shifts in these quantities with the adsorption process are determined by making comparisons with previous calculations for molecular CO. The shifts in the one-electron binding energies for the valence levels are typically ∼1 eV while the shifts in the two-hole final state binding energies are substantially larger, being typically ∼3–5 eV. Calculations are also performed for the Auger transition intensities. The changes that must be made for a fixed, oriented molecule on a surface are described and it is pointed out that some transitions exhibit a characteristic azimuthal angular dependence for the emitted Auger electrons.