Multiatom resonant photoemission: Theory and systematics

A first-principles calculation of the recently discovered interatomic multiatom resonant photoemission (MARPE) effect is presented. In this phenomenon, core photoelectron intensities are enhanced when the photon energy is tuned 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 electron 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 theory.This work was supported by the U.S. Department of Energy, under Contract No. DE-AC03-76SF00098, the University of the Basque Country, and the Spanish Ministerio de Educación y Cultura (Fulbright Grant No. FU-98-22726216).Peer reviewe