Applications of the relativistic equation of motion to photoionization of Mg-like ions Original Research Article

As an approximation to the relativistic equation of motion, the multiconfiguration relativistic random-phase approximation theory is applied to the valence-shell photoionization of the Mg-like ions. Photoionization cross sections between image and image ionization thresholds are calculated. The main feature of our results is exhibited by five Rydberg series of doubly excited states arising from fine-structure splittings. A comparative study of Al+, Si2+, P3+, S4+, Cl5+, and Ar6+ is presented.