Oscillator strengths for the magnesium isoelectronic sequence

Abstract

The relativistic random-phase approximation is used to calculate the excitation energies and absorption oscillator strengths for the $3{s}^{2}^{1}S_{0}\ensuremath{-}3s3p^{1}P_{1}$, -$3s4p^{1}P_{1}$, -$3s5p^{1}P_{1}$, and -$3s3p^{3}P_{1}$ transitions of selected elements of the magnesium isoelectronic sequence through nuclear charge $Z=92$. The results are compared with previous theoretical and experimental values. The data plotted as a function of ${Z}^{\ensuremath{-}1}$ enable us to study deviations from the predictions of the nonrelativistic $Z$-expansion theory.