Photoinization cross sections for atomic chlorine using an open-shell random-phase approximation

The use of the random-phase approximation with exchange (RPAE) for calculating partial and total photoionization cross sections and photoelectron angular distributions for open-shell atoms is examined for atomic chlorine. Whereas the RPAE corrections in argon ($Z=18\mathrm{}$) are large, we find those in chlorine ($Z=17\mathrm{}$) to be much smaller due to geometric factors. Hartree-Fock calculations with and without core relaxation are also presented. Sizable deviations from the close-coupling results of Conneely are found.