A Quasi-Classical Trajectory Dynamics Investigation Of Reactions O+HH And H+LiH And Their Isotopic Variants

This article mainly researches the dynamics of chemical reactions O(3~P) + HH (v = 0, j = 0-18) and H + LiH (v = 0, j = 0), including their scalar and vector properties. Chapters 1 and 2 give a brief introduction of molecular reaction dynamics, stereodynamics, quasi-classical trajectory theory and vector-correlation description. A simple presentation of Fortran code structure of quasi-classical trajectory method is also given in those above two chapters.In Chapter 3 we present the dynamics calculation results of reactions O + HH and O + DD. Reactive probabilities and reaction cross-sections of the two reactions are calculated. The cross-section computed for the reaction shows excellent agreement with previous results. Vector correlations, product rotational alignment parameters and four polarized dependent differential cross-sections were also calculated for the two reactions. The product polarization distribution exhibits different characters that can be ascribed to different motion paths on the PES arising from various collision energies or mass factors. With the increase of collision energy, not only the vector correlations of those reactions change, but also the direction of scattering changes from backward to forward.In Chapter 4 we present the dynamics calculation results of reactions H + LiH (v = 0, j = 0) H2 + Li reaction and its isotopic variants H + LiD Li + HD,D + LiH Li + DH and D + LiD Li + DD. The reactive probabilities, reaction cross-sections, one generalized polarization-dependent differential cross-section P00 are calculated. We found that different collision energies and mass factors show driving influence on the process of the reactions and product molecules H2 (HD, D2) polarization distribution, and the trend of the isotopic effects in the high collision energy range is different to that in the low collision energy range. The calculations are also interpreted in relation to the features of the underlying potential energy surface. We also observed the changes of vector correlations at different collision energies, and we compared the stereodynamics among different isotopic variants of the four reactions. With the increase of collision energy, the forward scattering increases of the for reaction products, but the middle and backward scattering has hardly any changes. The product polarization distribution of the four reactions exhibits distinct difference which may arise from different mass combinations or kinetic energies.