Calculations of transition probabilities for forbidden lines in the 3d7 ground configurations of Co III and Ni IV

Calculations of magnetic dipole and electric quadrupole transition probabilities for 'forbidden' lines in the 3d7 ground configurations of Co III and Ni IV are presented. The calculated A factors, which are believed to be the most accurate presently available, are based on parametric fitting to the observed energy level structure and Hartree-Fock values for the electric quadrupole moments. In the course of this work, the only term hitherto missing in the two configurations, the high 1(2)D term in Co III, was established from new laboratory measurements of the Co III emission spectrum.