A THEORETICAL DESCRIPTION OF THE LOWEST LYING ELECTRONIC STATES OF THE BEH2+ DICATION

The four lowest lying electronic states of the BeH2+ dication are desc ribed theoretically using the multireference single and double excitat ions configuration interaction approach. Only the ground state shows a potential energy well; this well is very shallow and supports at leas t eight vibrational levels. Although the ground state is thermodynamic ally unstable, this potential well arises as the interaction between t he potential energy curves representing the structures BeH+ -H+ and Be 2+ -H. Dipole and transition moment functions are also calculated for all states and radiative transition probabilities and lifetimes are co mputed for rovibrational transitions in the ground electronic state; v ibrational and rotational constants are also reported for this state.