On the low lying singlet states of BeO

Using a Gaussian basis set of slightly better than double zeta plus polarization quality, MCSCF and CI calculations were performed for the ground and several low-lying singlet states of BeO. The computed separations for X, A, and B states are in good agreement with experiment. The 1Σ - and 1Δ states are predicted to lie ∼40 000 cm-1 above the X state, while the 2 1Π and 3 1Σ+ are predicted to lie 56 000 and 65 000 cm -1 above the X state, respectively. © 1980 American Institute of Physics.