Multiatom resonant photoemission: Theory and systematics

A first-principles calculation of the recently discovered interatomic multi atom resonant photoemission (MARPE) effect is presented. In this phenomenon , core photoelectron intensities are enhanced when the photon energy is tun ed to a core-level absorption edge of nonidentical neighboring atoms, thus enabling direct determination of near-neighbor atomic identities. Both the multiatom character of MARPE and retardation effects in the photon and elec tron interactions in the resonant channel are shown to be crucial. Measured peak-intensity enhancements of 40% in MnO and spectral shapes; similar to the corresponding x-ray absorption profiles are well reproduced by this the ory.