RELATIVISTIC CONFIGURATION-INTERACTION CALCULATIONS OF POTENTIAL CURVES AND RADIATIVE TRANSITION-PROBABILITIES FOR THE ANTIMONY FLUORIDE MOLECULE

An ab initio configuration interaction treatment is reported for the antimony fluoride molecule employing relativistic effective core potentials (RECPs) including spin-orbit coupling. Potential curves for the lowest nine OMEGA states are obtained and good agreement with experimental values for bond lengths (0.01-0.02 angstrom) and vibrational frequencies (+/- 30 cm-1) is noted. Observed multiplet splittings for X3SIGMA- and A 3PI are reproduced well in the computations, showing the regular order expected from the latter's pi*sigma* electronic configuration; the absolute T(e) values for A-X transitions are uniformly overestimated by 1200 cm-1 (0.15 eV). Radiative transition probabilities computed with the corresponding vibrational wavefunctions are consistent with empirical rules given by Colin and co-workers for the relative intensities of b0+-X10+, X(2)1 band systems. These results are compared with analogous findings for the heavier bismuth fluoride system, for which an exception to the above rule has been observed, and the theoretical basis for these trends is discussed.