Photoionization 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) are large, it is found that those in chlorine (Z=17) are 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 also found.