Z-DEPENDENT DIFFERENCES BETWEEN EXPERIMENTAL AND THEORETICAL 2P-CORE-HOLE WIDTHS OF ATOMIC RARE-EARTHS

The x-ray absorption spectra of the atomic rare earth cerium, samarium, gadolinium, erbium and ytterbium were measured for photon energies close to the 2p threshold. Correcting for the instrumental broadening, the widths of the white lines were determined. Except for cerium, these experimental widths fall below the theoretical total L level widths. Combining the available experimental data for the elements between Xe (Z = 54) and Hg (Z = 80) and new data on Xe it is demonstrated that theory and experiment agree for atomic numbers Z greater-than-or-equal-to 70 but differ for the low-Z elements.