Relativistic oscillator strengths forE1transitions in the argon isoelectronic sequence

Abstract

The relativistic electric dipole oscillator strengths in length and velocity forms are calculated for a number of elements in the argon sequence. The transitions studied are $3{p}^{6}\ensuremath{-}3{p}^{5}\mathrm{nd}$ $(n=3, 4)$ and $3{p}^{6}\ensuremath{-}3{p}^{5}4s$. The ground state includes correlation due to the configuration $3{p}^{4}3{d}^{2}$ in computing $p\ensuremath{-}d$ transitions. Relativistic effects on line strengths are found to be important in the $\ensuremath{\Delta}n\ensuremath{\ne}0$ transitions even at low $Z$. The origin of these large relativistic effects for low $Z$ in the $3{p}^{6}\ensuremath{-}3{p}^{5}4l$ transitions are discussed.