Determination of theoretical transition probabilities for the Pb III spectrum

Theoretical values of absolute transition probabilities for 54 lines arising from the 6s np configuration of Pb III have been obtained. These values were obtained in intermediate coupling (IC) and using ab initio relativistic Hartree-Fock calculations. We used for the IC calculations the standard method of least square fitting of experimental energy levels by means of computer codes from Cowan. These values, although in general agreement with the rare experimental data, do present some noticeable discrepancies. Analysis of the interaction between ¹D₂ levels of 6p² and 6s6d configurations shows a 40% contribution from the 6s6p² configuration for the lowest one, and a 27% contribution from 6s6d for 6s6p²