ON THE ASSIGNMENT OF TRANSITIONS INVOLVING SOME (2)PI RYDBERG STATES OF THE BEH MOLECULE

Very accurate potential energy curves for several low-lying excited (2 ) Pi states of the BeH molecule are reported using the multireference configuration approach. New features in the potential energy curves of the B and G (2) Pi states not considered previously, like the existen ce of a double minimum, invalidate some of the arguments used in the a ssignment of transitions arising from these states. An alternative int erpretation of some of the transitions and improved spectroscopic cons tants are presented. For the 3d states, for which experimental data ar e still uncertain about their nature, this study allows us to make an unambiguous correlation with the 3d (2) Pi state. (C) 1998 Elsevier Sc ience B.V.