Theoretical study of the X(2)B(1), A(2)A(1) and B-2(2) states of H2Se+

Three-dimensional potential energy functions for the lowest X(2)B(1), A(2)A(1) and B-2(2) states of the H2Se+ radical cation have been generated by ab initio calculations and used in the evaluation of the spectroscopic constants of the X(2)B(1) and A(2)A(1) states. Variationally calculated vibrational levels up to 10 000 cm(-1) of the X stale and the low lying vibrational levels of the A state are reported. The largest absolute line intensities obtained from theoretical dipole moment functions and rovibrational wave functions are given for the fundamental vibrational transitions.