A simple model for the quantitative evaluation of the XPS line shape asymmetries in nearly free electron and noble metals

We show that the Born approximation for the scattering by a linearly screened simple model “hole” potential, derived by pseudopotential data, is sufficient to provide an accurate evaluation of the XPS line shape asymmetry parameter α. We get a simple analytical close form expression for α as a function of r_s, which emphasizes the role of electronic screening and evidentiates that α is increasing with increasing r_s.