SENSITIVITY OF THE F+H-2 REACTION PROBABILITY TO THE POTENTIAL SURFACE

The method of functional sensitivity analysis is used to identify the areas of reactive significance on the T5A potential. The influence of various regions of the potential upon the total integrated reaction probability of F + H-2 (v=0, j=1) is examined for collision energies in the range 0.032-0.066 eV and for total angular momentum J=5 and 10. Several regions are identified as having particularly strong influence on the reaction probability at these energies. The most influential region is, as expected, the saddle point and the approaching slope. The HF(v'=3) adiabatic exit barrier region and the region between the saddle point and the exit barrier are also confirmed to be important. While upward adjustments of the potential in either of the barrier regions would lower the predicted probability of reaction, increasing the potential in the interbarrier region would raise the reaction probability. Among nearly collinear arrangements, the inner wall of the exit valley, which includes the effective turning point at the end of the entrance valley, exerts surprisingly large influence on the reaction probability. Implications of these results for refinement of the potential are discussed.