Barrier effects on the vibrational predissociation of HD2+

The vibrational predissociation of HD2 + is modelled in terms of quantum-mechanical tunnelling through a minimal centrifugal barrier at given total angular momentum, J, and with statistical intermode coupling behind the barrier. It is shown that the observed strong preference for the H+ + D 2 predissociation channel (over D+ + HD) is consistent with an experimental preference for J values in the range 0 < J < 25, a range which is also shown to be consistent with the observed H3 + preferred range of kinetic energy release. A correlation between the total angular momentum and the kinetic energy release is also predicted.