PNNL

Abstract

The role of ligand field effects and many-body effects arising from angular momentum coupling and shake effects for the XPS of NiO, as a representative transition metal oxide, have been investigated using rigorous, non-empirical wavefunctions for single site cluster models. It is shown that important features of the XPS arise from proper treatment of angular momentum coupling and it is completely unnecessary to invoke non-local screening to explain the experimental XPS Contrary to the usual understanding, it is shown that inclusion of shake excitations in the many body wavefunctions is responsible for the high BE satellites that are observed. The contribution of covalent mixing of metal and ligand orbitals in the closed shells to screening of core-holes is demonstrated.