Atomic transition probabilities in BiII

Using the Hartree-Fock method with relativistic corrections and the multico nfiguration 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 fitt ing procedure, as well as the highly systematic restrictive active space ap proach coded in GRASP92, have been applied to this complex heavy ion and ha ve allowed to predict gf-values probably accurate within a few percent. The importance of both correlation and relativistic effects is stressed. The g ood agreement between the two sets of data is an argument in favour of thes e new results and throws some light upon the accuracy accessible in calcula tions of this type. Detailed comparisons with previous experimental or theo retical data, when available, are also considered and some discrepancies th eory - experiment are tentatively explained.