Molecule coordinate frame anisotropy in dissociative photoionization of CF3I

Lifetimes of long-lived collision complexes of H⁺ + H₂ and some isotopic variants have been determined from classical trajectory calculations. A lifetime range of 0.1–50 ps could be covered, while a typical vibrational period of the complex is 10 fs. The results in agree with the expectation from RRKM theory: independence of τ of the origin of the energy of the complex (translation, vibration, or rotation), and a power law dependence of τ on E/(E + D) with exponent 2. A closer look shows a dependence of τ on total angular momentum J, which is also the main reason for non-exponential decay curves of samples for which J is not specified, and for much of the apparent dependence of τ on mass distributions. Our data show that an induction time is needed before the complex obtains its (statistical) properties.