Photoionization of the Be isoelectronic sequence from the ground and the 1S bound excited states.

Abstract

Theoretical photoionization spectra below the 2p threshold of the Be isoelectronic sequence from the ground and a few selected $^{1}$S bound excited states are calculated using a B-spline-based configuration-interaction approach. The resonant structures of the doubly excited autoionization series following photoionization from different initial states are analyzed in detail in terms of various initial- and final-state multielectron interactions. In addition, our calculation has shown that the resonant widths vary smoothly as functions of the effective principal quantum number \ensuremath{\nu} along the autoionization series and approach approximately an expected ${\ensuremath{\nu}}^{\mathrm{\ensuremath{-}}3}$ dependence as \ensuremath{\nu} increases.