Photoionization Study of S4+ Ions Using the Modified Atomic Orbital Theory

The single photoionization of S V ions into S VI is investigated in this paper within the framework of modified atomic orbital theory (MAOT). The theoretical resonance energies, quantum defects and effective nuclear charges of the autoionizing Rydberg series 2s22p53s2nd (1P1, 3D1), 2s22p53s2ns (1P1, 3D1) and 2s2p63s2np (1P1) resulting from the 2p → nd, 2p → ns and 2s → np transitions respectively in the 2s22p63s2 (1S0) ground state of S4+ are reported. The present results are in excellent agreement with experimental synchrotron radiation measurements and theoretical calculations (MCDF and R-matrix) by Mosnier et al. (Phys Rev A 106:033113, 2022). The newly tabulated MAOT data up to n = 40 are relevant for both laboratory and astrophysical plasmas.