Relativistic multireference many-body perturbation theory calculations on ions of the phosphorus isoelectronic sequence
Term energies of the ground and excited states arising from the 3s23p3, 3s3p4, 3s23p23d and 3s3p33d configurations in ions of the phosphorus isoelectronic sequence (Z = 26-32) are evaluated in relativistic multireference many-body perturbation theory calculations. Theory deviates from experiment on the order of 0.01% for the majority of the experimentally identified levels. The term energies of the 12 hitherto unidentified 3s23p23d levels are determined with 0.01% accuracy. Theoretical photon wavelengths of the electric-dipole (E1) decays from the 3s23p23d and 3s3p33d levels are compared with laboratory and solar lines to critically evaluate previous line identifications. A number of new solar line identifications are given on the basis of theoretical wavelengths and transition probabilities. Theoretical lifetimes of 39 levels arising from the 3s3p4, 3s23p23d and 3s3p33d configurations are evaluated. For the 3s23p23d 4F7/2, 4D7/2 and 4G7/2 levels in Fe XII, Co XIII and Ni XIV, theoretical lifetimes exhibit significant deviation from those obtained in a recent fast-beam spectroscopy experiment.