Theoretical studies of bimolecular reaction dynamics

The reduced dimensionality (CEQB) theory of atom-diatom reactive scattering is implemented and applied to D+H{dollar}sb2{dollar}, H+D{dollar}sb2{dollar} and Cl+HCl reactions. Converged rate constants, using this new version of the theory, for the first two reactions, initially at vibrational state v = 0 between 200-2000K, and initially at vibrational state v = 1 between 200-600K, are obtained and these results are used to test the CEQB/G theory. Similar calculations are also done for these two reactions using the most accurate potential surface, the DMBE surface, and the thermal rate constants are in very good accord with experimental results between {dollar}sim{dollar}200-2000K, which confirms the accuracy of CEQB theory. The accuracy of the CEQB theory is also testified by comparing cumulative reaction probabilities and thermal rate constants of CEQB theory with those of the centrifugal-sudden distorted-wave method and the accurate coupled channel hyperspherical method on the Cl+HCl reaction using two semiempirical potential surfaces. In addition, the dynamics and kinetics of these reactions are studied.; A hypercylindrical coordinate system is introduced to describe quantum diatom-diatom reactive scattering, in which one diatom bond is assumed to be non-reactive, in both three dimension and reduced dimensionality space. One theory in the reduced dimensionality space, i.e., the collinear diatom-diatom reactive scattering theory, is applied to a model H{dollar}sb2{dollar}+A{dollar}sb2to{dollar} H+HA{dollar}sb2{dollar} reaction. Convergence tests, reaction probabilities, and some dynamics studies are given. Based on the combination of the collinear theory and the adiabatic bend approximation, a reduced dimensionality theory for diatom-diatom reactive scattering is developed and also applied to dynamics studies of the H{dollar}sb2{dollar}+CN {dollar}to{dollar} H+HCN reaction using a newly-developed global potential surface which is based on both ab initio calculations and experiments.