ON THE CALCULATION OF FINAL-STATE FREE ATOM METAL SHIFTS OF CORE LEVELS

Final state free atom solid phase shifts of core electron binding and Auger kinetic energies of metallic elements are analyzed via the calculation of relaxation energies. Intra- and extra-atomic contributions to the single-hole (photoemission) and cross- (Auger emission) relaxation energies have been calculated using an atomic density functional theory formalism combined with the "excited atom" model (for the extra-atomic part). From the present results, some non-linear effect (positive for the intra-atomic, and negative for the extra-atomic part), must be added to a purely coulombic model in order to describe correctly the electron response to hole perturbation. The comparison with earlier work is carried out in two ways. Firstly, comparison of extra-atomic relaxation energies with those obtained by other calculations, such as jellium and excited atom models, shows good agreement. As for experiments, the results are consistent with the values of the Auger parameter deduced from XPS measurements.