Theoretical analysis of lineshape in core-electron shake-up spectra: Ne 2s-3s satellite

. A theoretical analysis of the recently recorded high-resolution shake-up spectrum
of Ne is presented in order to quantitatively explain the observed asymmetric line profile
of the 2s-3s satellite. Ab initio calculations based on the sudden approximation, the
static-exchange approximation and ihe X-matiix iiiethod i+%h sqzare in:eg:ab!e basis sets,
confirm that the coupling of the discrete shake-up state with the underlying shake-off
continua is the main reason for the unusually large linewidth observed. The lineshape
calculated according to the Fano approach is in very good agreement with the experimental
one, showing that the proposed Theoretical and computational scheme can be satisfactorily
applied to the description of core level photoelectron spectra.