The electronic excited states of BN

The a(1) Sigma(+)-X(3)II separation is estimated to be 180 +/- 110 cm(-1), which is in reasonable agreement with the recent experimental determination that the separation in a neon matrix is between 15 and 182 cm(-1). The calculated spectroscopic constants for the excited states confirm the experimental assignment for the triplet states below 30000 cm(-1) and two lowest singlet states. On the basis of a comparison of the computed results with those obtained from experiment, the computed spectroscopic constants for the higher electronic states should be sufficiently accurate to help in the assignment of future experiments.