Relativistic-random-phase approximation calculations of atomic photoionization: what we have learned

The relativistic-random-phase approximation (RRPA) methodology, developed by Walter Johnson and his collaborators, has been used extensively over the past three decades to calculate various aspects of the atomic photoionization process, cross sections, and branching ratios along with dipole and nondipole contributions to the photoelectron angular distribution. In this paper, some of the progress made in our understanding of the photoionization process as a result of RRPA calculations is reviewed.PACS No.: 32.80.Fb