Excitation energies and line strengths in the Mg isoelectronic sequence

Abstract

Excitation energies and line strengths for the low-lying states of ions in the Mg isoelectronic sequence are studied using relativistic multiconfiguration Hartree-Fock techniques. Line strengths for all possible electric dipole transitions between these low-lying states are calculated in both the length gauge and in the velocity gauge along the sequence from Mg to ${\mathrm{U}}^{+80\mathrm{}}$, and the results show good agreement between these two forms of line strength for all cases considered. At low $Z$, the results of the present work are in good agreement with other recent theoretical calculations. The results of this work are expected to give accurate excitation energies and line strengths at high $Z$ as well since relativistic effects are treated nonperturbatively.