Dependence of reaction attributes, including differential cross sections and resonance features, on changes in the potential energy surface for the F+D₂ reaction

We present a series of comparisons of dynamical reaction attributes for the reaction F+D₂→FD+D. We employ three potential energy surfaces, Muckerman surface no. 5 and two surfaces suggested more recently. These surfaces differ in barrier height and bending potential. The dynamical calculations are based on the quasiclassical trajectory method and on the bend-corrected rotating linear model. We find that new surface no. 2 does allow for significant reaction probability at 0.8 kcal/mol, as required to agree with molecular beam experiments. The wider bending potential of new surface no. 2 does not, however, have a large effect on the angular distribution. Although it is known from previous work that the barrier in the entrance channel is important for the compound-state resonance in this reaction, lowering the barrier from 1.06 kcal/mol in Muckerman surface no. 5 to 0.74 kcal/mol in the new surfaces does not make a qualitative change in the resonance features of the results. We conclude, on the basis of this paper and previous studies of the thermal rate constants, that new surface no. 2 is more accurate than the widely studied Muckerman surface no. 5 and provides a better starting point for future work.