Relativistic MR-MP energy levels: Low-lying states in the Mg isoelectronic sequence

The relativistic Multi-Reference Møller–Plesset (MR-MP) many-body perturbation theory was applied to calculate the energies of all excited states within the 3s3p, 3p2, 3s3d, 3p3d and 3d2 configurations for every ion of the Mg isoelectronic sequence (Z=12−100Z=12−100). The results are compared with previous calculations and available experimental data. The MR-MP excitation energies agree with experiment typically within 100 ppm over a wide range of ZZ, particularly for mid- and high-range ZZ. Experimental data for highly charged ions in this isoelectronic sequence are limited and the complete and accurate dataset presented here is expected to ease the identification process upon measurements.