Atomic transition probabilities in BiII

Using the Hartree-Fock method with relativistic corrections and the multiconfiguration Dirac-Fock fully relativistic approach, a detailed analysis of Bi II transition probabilities of astrophysical interest is presented. The relativistic Hartree-Fock approximation, combined with a least-squares fitting procedure, as well as the highly systematic restrictive active space approach coded in GRASP92, have been applied to this complex heavy ion and have allowed to predict gf-values probably accurate within a few percent. The importance of both correlation and relativistic effects is stressed. The good agreement between the two sets of data is an argument in favour of these new results and throws some light upon the accuracy accessible in calculations of this type. Detailed comparisons with previous experimental or theoretical data, when available, are also considered and some discrepancies theory - experiment are tentatively explained.