Ab initio MCDHF/RCI and semi-empirical HFR calculations of transition probabilities and oscillator strengths in Xe XI

The atomic structure of ten-times ionized xenon (Xe XI) has been computed by two independent methods, i.e. the ab initio relativistic multiconfiguration Dirac–Hartree–Fock (MCDHF) approach within the relativistic configuration interaction (RCI) approximation and the semi-empirical pseudo-relativistic Hartree–Fock (HFR) method. The transition probabilities and oscillator strengths of the 4d8 − (4p54d9 + 4d75p + 4d74f) transition array have been determined in both models and allowed us to estimate their accuracy taking into account both the gauge agreements and the cancellation effects on the line strengths. It has been found that core – core and core – valence correlations through the explicit inclusion of single- to triple-hole 4p-subshell configurations in our RCI model systematically decrease the transition rates by about 20% for the strong lines (with log gf > 0) with respect to our HFR values that did not consider those effects. Further opening of the core shells has also been investigated and did not give rise to significant systematic change on the transition probabilities. © 2019 Elsevier Ltd