QUANTUM DYNAMICS OF O(P-3)-]OH+CL - EFFECTS OF REAGENT ROTATIONAL-EXCITATION(HCL)

Accurate quantum dynamics of the chemical reaction O(P-3) + HCl(j(i), v(i) = 0) --> CH(j(f), v(f) = 0) + Cl is studied using the hyperspheri cal coordinate approach and the Koizumi-Schatz-Gordon (KSG) potential- energy surface. The effects of reagent rotational excitation on the dy namics are investigated. The study considers total energies up to 0.7 eV and reagent rotational states, j(i) = 0-10. The total reaction cros s-section shows a strong dependence on j(i). Initially it decreases wi th increasing j(i), up to j(i) approximate to 4, and then increases wi th further increase in j(i). This overall trend is enhanced on increas ing the total energy. The final rotational state (j(f)) distributions are also investigated. Interestingly, the distribution shows a peak at high j(f) (approximate to 10) irrespective ofj(i) and the total energ y. The qualitative features are quite similar to the experimental resu lts. Finally, the state-resolved rate constant and the thermal rate co nstant are evaluated. Because of the enhancement of the reaction by th e reagent rotational excitation, the state-resolved rate constants for 8 less than or similar to j(i) less than or equal to 10 are two or th ree orders of magnitude larger than those for j(i) less than or simila r to 5. The thermal rate constant obtained is thus much larger than th e experimental data implying that the barrier height of the KSG surfac e may be too low.