Theoretical study of the spectroscopy and radiative transition properties of NS.

Abstract: The low-lying electronic states (X 2Π, a 4Π, b 4Σ−, B 2Π, 12Φ, A 2Δ and B′2Σ+) of the NS molecule are computed at the AV5Z/CASSCF/MRCI+Q+DK level of theory. The potential energy curves are presented for these states; the corresponding spectroscopic constants are reported. Electronic transition moment functions, Einstein coefficients, Franck–Condon factors and radiative lifetimes for the B 2Π–X 2Π, B′2Σ+–X 2Π and A 2Δ–X 2Π system have been calculated. The F–C factors of the B 2Π are in good agreement with the corresponding RKR data. The B′2Σ+ state possesses a barrier in the potential energy curve, located at about 2.16Å. The height of the barrier is predicted to be 7890cm−1. [Copyright &y& Elsevier]