Cross-correlation trajectory study of vibrational relaxation of DF(v = 1 to 7) by DF(v = 0) and of HF by HF

Three-dimensional quasiclassical trajectories and a cross-correlation method of analysis are used to study the vibrational relaxation of DF(v1 = 1 to 7) by DF(v2 = 0). Rate constants are calculated for V–V and V–R, T energy transfer. As was seen in earlier studies on HF–HF, the V–R, T mechanism becomes increasingly important at higher initial v1, as the V–V transfer moves further off resonance and also becomes increasingly endothermic. Both factors contribute to the decrease of V–V transfer rates with increasing v1 for the higher values of v1. Comparisons are made with results of a classical path study of vibrational relaxation in DF–DF and with experiment where possible. New results on the HF–HF V–V transfer rates are presented.