ON THE LOW-LYING ELECTRONIC STATES OF THE MOLECULE BEN

Using the multireference singles and doubles configuration-interaction approach, this study presents for the first time reliable theoretical evidence of the existence of a new molecular species, BeN. Potential-energy curves, vibrational energy spacings, dissociation energies, dipole moments, and the associated spectroscopic constants are reported for the first ten lowest electronic states. Comparisons with other isoelectronic diatomics are presented. Perturbative effects are expected to play a non-negligible role in the spectroscopy of this molecule due to the closeness of the electronic and vibrational states. The global picture of the electronic states presented will certainly be an important aid to the experimentalist to search for this molecule.