Angular momentum dependence of unimolecular decay in a triatomic system

Abstract

Classical trajectory calculations were performed to determine the lifetime τ of long-lived collision complexes in H⁺-D₂ or D⁺-HD collisions. For the same complex characterized by total energy and total angular momentum, the lifetimes are independent of (a) the kind of energy supply (i.e. translational or vibrational), and (b) the distribution of the three masses into projectile and target. It was found that τ(J) increases monotonously with J, first linearly, then faster, finally proportional to (J _max - J)^-1. The shape of τ(J) can be understood in terms of statistical theory if the overall rotation is included in the assumed quasi-equilibrium.