Accurate multiconfiguration Dirac-Fock calculations of transition probabilities in the Mg isoelectronic sequence

Results from valence and core-valence multiconfiguration Dirac-Fock and relativistic configuration interaction calculations including the Breit interaction are presented for the 3s(21)S(0)-3s3p(1)P(1) and 3s(21)S(0)-3s3p(3)P(1,2) transitions (E1, M2) in the Mg isoelectronic sequence. In the calculations the orbital sets of the initial-and final-state wavefunctions were not restricted to be the same, but were optimized independently. The evaluation of the transition matrix elements was done with an efficient transformation technique. The calculated energy separations and transition probabilities are found to be in good agreement with experiment and compare favourably with other recent calculations. For completeness, results for forbidden transitions (E2, M1) within the 3s3p P-3 fine-structure levels are also included.