Katsuyuki NOBUSADA, Kengo MORIBAYASHI (NIFS, Nagoya) and Hiroki NAKAMURA
[J. Chem. Soc. Faraday Transactons 93, 721 (1997)]
Accurate quantum dynamics of the chemical reaction O (3P) + HCl (ji, vi=0) -> OH (jf,vf=0) + Cl is studied using the hyperspherical coordinate approach and the Koizumi-Schatz-Gordon (KSG) potential-energy surface. The effects of reagent rotational excitation on the dynamics are investigated. The study considers total energies up to 0.7 eV and reagent rotational states, ji=0-10. The total reaction cross-section shows a strong dependence on ji. This overall trend is enhanced on increasing the total energy. The final rotational state (jf) distributions are also investigated. Interestingly, the distribution shows a peak at high jf(~~ 10) irrespective of ji and the total energy. The qualitative features are quite similar to the experimental results. Finally, the state-resolved rate constant and the thermal rate constant are evaluated. Because of the enhancement of the reaction by the reagent rotational excitation, the state resolved rate constants for 8 ~< ji =< 10 are two or three orders of magnitude larger than those for ji=5. The thermal rate constant obtained is thus much larger than the experimental data implying that the barrier height of the KSG surface may be too low.