Multielectron correlation effects in Xe2+ formation resulting from the photoionization of Xe+ ions

It is demonstrated that the photoionization of Xe+, leading to Xe2+, is com pletely dominated by interchannel coupling between the strong 4d ionization channels and the valence 5s and 5p channels. Calculations were performed u sing the random-phase approximation with exchange (RPAE), generalized to ap ply to open-shell systems, which included ionization from 5p, 5s and 4d sub shells in S-2, P-2 and D-2 final channels. The results showed that Hartree- Fock cross sections are not even qualitatively correct over an energy regio n of similar to 100 eV. Comparison with (relative) experimental data shows quite reasonable agreement.