The isotope effect on the photoassociation of X + F → XF (X = H, D)

Abstract

The photoassociation (PA) reactions of H + F → HF and D + F → DF are investigated by using the time-dependent quantum wave packet method. For each system, we consider four cases, where the target state is set to be ∣ν = 16, 17, 18, 19〉, respectively. The effects of the initial collision momentum and laser parameters, including intensity, pulse duration, and frequency, on the final association probability are calculated and discussed. It is found that the PA probability for H + F → HF (∣ν = 16, 17, 18〉) is significantly greater than that for D + F → DF (∣ν = 16, 17, 18〉), while the PA probability to ∣ν = 19〉 for the latter system is greater than the former one. This isotope effect has been connected with the Franck–Condon overlap integral between the target vibrational state and the collision continuum state.