The role of asymptotic vibrational states in H3+

Calculations are discussed which characterize all the vibrational bound states of the H-3(+) and D2H+ molecular ions using a realistic ab initio potential energy surface. Graphical analysis and calculation of rotational constants show that both ions support a series of atom-diatom-like long-range states: asymptotic vibrational states. The role of these states in the H-3(+) system and other molecules is discussed. The vibrational calculations are extended above dissociation where the resulting (Feshbach) resonances are shown to be too short-lived to be of importance for the H-3(+) photodissociation spectrum.