ACCURATE QUANTUM DYNAMICS OF THE LIGHT ATOM-TRANSFER CHEMICAL-REACTION O-]OH+CL(HCL)

The hydrogen atom transfer reaction between two heavy atoms, upsilon(i )=0j(i)=0-2)-->OH(upsilon(f)=0,1j(f))+Cl, is studied quantum mechanica lly accurately with use of the hyperspherical coordinate approach, whe re upsilon(lambda) and j(lambda) designate the vibrational and rotatio nal quantum numbers in the lambda arrangement channel. The collision e nergy considered in this study ranges up to similar to 0.7 eV, and the total angular momentum J is required up to similar to 120. The potent ial energy surface employed is the one derived by Koizumi, Schatz, and Gordon (KSG) based on ab initio data. The effects of the potential en ergy surface topography on the dynamics are analyzed in terms of the c ollision energy dependence and the j(i) dependence. The effects of the nonlinearity of the transition state of the KSG surface is clearly ma nifested in these dynamics. Not only the accurate integral cross secti on and the rate constant are evaluated, but also the Omega(i) dependen ce of the dynamics and final rotational state distribution are analyze d, where Omega(i) is the z-component of J in the initial arrangement c hannel. The j(f) distribution at E(coll)greater than or equal to 0.5 e V shows an interesting resemblance with the feature recently observed experimentally. The energy-shift approximation is extended so as to co ver the general triatomic systems which require a large number of J. T his extended CCPA (constant centrifugal potential approximation) is sh own to work well.