A theoretical description of the lowest lying electronic states of the BeH2+ dication

The four lowest lying electronic states of the BeH 2+ dication are described theoretically using the multireference single and double excitations configuration interaction approach. Only the ground state shows a potential energy well; this well is very shallow and supports at least eight vibrational levels. Although the ground state is thermodynamically unstable, this potential well arises as the interaction between the 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 computed for rovibrational transitions in the ground electronic state; vibrational and rotational constants are also reported for this state.