L(3) EDGE X-RAY-ABSORPTION SPECTRUM OF CEO2 - CRYSTAL-STRUCTURE EFFECTS

We report the interpretation of all spectral features of Ce L(3) XANES over the 40 eV range. The wave function of the excited electron in th e final states of the Ce L(3) edge XANES spectrum is found to be deter mined by the multiple-scattering processes in a large size cluster for med by at least 45 atoms. The many-body final states for the 2p --> 5, epsilon d transition, arising from the configuration interaction due t o mixing of Ce 4f and O 2p valence orbitals, have been recalculated ta king into account the crystal held splitting of the 5,epsilon d states . The results give full explanation of the low energy shoulder on the Ce L(3) XAS white line that was object of a long-standing discussion.