LARGE-SCALE RELATIVISTIC CONFIGURATION-INTERACTION CALCULATION OF THE3S(2) S-1(0)-3S3P P-1,3(1) TRANSITION ENERGIES IN MAGNESIUMLIKE IONS

We have calculated the 3s(2 1)S(0)-3s3p(1,3)P(1) transition energies f or neutral magnesium and Mg-like Ar6+, Cu17+, Kr24+, and Mo30+ using t he relativistic configuration-interaction (CI) method. These calculati ons are based on the relativistic no-pair Hamiltonian which includes C oulomb and retarded Breit interactions and employ finite B-spline basi s functions. Quantum electrodynamic and mass polarization corrections are also calculated. For Mg-like ions studied here, intravalence corre lations are treated exactly by saturating the basis with all configura tions that arise from valence-valence excitations. Contributions from core polarization are also calculated with large-scale CI expansions b y including dominant configurations from core-valence excitations. Agr eement between theory and experiment are good for all the Mg-like ions studied here.