Relativistic many - body calculations of energy levels , hyperfine constants , and transition rates for sodiumlike ions , Z 5 11 – 16

All-order relativistic many-body calculations of removal energies are carried out for 3s , 3p1/2 , 3p3/2 , 3d3/2 , 3d5/2 , and 4s states of sodium and sodiumlike ions with nuclear charges Z in the range 12–16. Hyperfine constants are evaluated for each state, and reduced dipole matrix elements are determined for 3p1/2-3s , 3p3/23s , 3d3/2-3p1/2 , 3d3/2-3p3/2 , 3d5/2-3p3/2 , 4s-3p1/2 , and 4s-3p3/2 transitions. The calculations include single and double excitations of the Hartree-Fock ground state to all orders in perturbation theory. Corrections to energies are made for a dominant class of triple excitations. The Breit interaction, with all-order correlation corrections, is evaluated. Reduced-mass and mass-polarization corrections are included to third order in perturbation theory. The predicted removal energies, when corrected for the Lamb shift, agree with experiment at the 1–20-cm level of accuracy for all states considered. Theoretical fine-structure intervals agree with measurements to about 0.3% for 3p states and to about 3% for 3d states. Theoretical hyperfine constants and line strengths agree with precise measurements to better than 0.3%. @S1050-2947~98!01308-0#