Theoretical study of excited singlet states of H + 3 Potential surfaces and transition moments

Ab initio calculations of 13 singlet states of H⁺₃ in C_2v symmetry are reported. The diabatic correlation diagram linking the states at the ground state equilibrium D_3h symmetry to those at the H₂+H and three-body asymptotes has been established by careful analysis of the excited state wave functions. Transition moments between the two lowest states and those connecting the diabatic states arising from H⁺₂ +H(n=2) and the lower states have been evaluated. Radiative lifetimes of the excited states have been estimated. Implications for observing photodissociation of H⁺₃ are discussed.