Energy levels and radiative rates for transitions in S-like Sc~VI, V VIII, Cr IX, and Mn~X

Abstract

Energy levels, radiative rates and lifetimes are reported for four S-like ions, namely Sc~VI, V VIII, Cr IX, and Mn~X. Two independent atomic structure codes, namely the general-purpose relativistic atomic structure package ({\sc grasp}) and the flexible atomic code ({\sc fac}), have been adopted for calculating the energy levels, with differing amounts of configuration interaction. This is mainly to make some assessment of accuracy. However, the {\sc grasp} alone is used for calculating the remaining parameters. Results are reported for varying number of levels of these ions, and for calculating lifetimes contributions are included from all types of transitions, i.e. E1, E2, M1, and M2. Comparisons are made with the earlier available experimental and theoretical results and assessments of accuracy are given for each ion. Additionally, the presently reported data cover a significantly larger number of levels and transitions than already available in the literature for the four S-like ions.