Molecular Dynamics Study Of The Reactions Of H+HS And Its Isotopic Variants

In this thesis, we have fitted the potential energy curves of diatomic molecular HS(2∏) and HH(X1∑+) and the Potential Energy Surface (PES) of the three atomic system, with the global potential energy surface fitting codes of of Alfredo et al. As the results says, the potential energy curves of H2(X1∑+) and HS(2∏) obtained is relatively accurate compared with the accordingly experimental values. The most important character of the PES from Ho et al is the existence of the deep potential well, and the potential well with similar depth have been found in our fitting results of H2S(1A’).The stereodynamics of H+H’S(v=j=0)�'HS+H’and its isotopic variants reactions have been studied using quasiclassical trajectory (QCT) method on the1A’ potential energy surfaces constructed by Ho et al. The results calculated by the quantum method time dependent wave packet method (QM TDWP) have been given combined with the QCT results for more profound understanding of the H+H’S reaction. The scalar properties, the vector properties and the correlation of the vectors have been calculated and discussed. Furthermore, the influence of the collision energy, isotopic effect and the initial excitation effect on the stereodynamics has also been calculated.In the investigation of the reaction H+H’S(v=j=0)�'HS+H’, the QCT results describing the energy dependent behavior of ICSs fit well with the QM results. The crucial role of the PES in the vectors correlation properties have been founded in our calculation on the stereodynamics distribution functions. The existence of the long lived complex means the indirect reaction mechanism of this reaction. And the distributions functions of the polar angle and dihedral angle imply that the rotation angular momentum of the product molecular point preferentially to the positive or negative direction of y-axis. The QCT results of reaction D+HS�'DS+H and its isotopic reaction H+DS�'HS+D in the same PES have been shown in this thesis. The role of PES in influencing the scattering directions of the products is decisive, and the weak influence of mass factor and energy factor have been obtained through comparing the DCSs of two reactions. We have presented detailed discussion about the distribution of product polarization describing the alignment and orientation of the product rotational angular momentum, and one can conclude the influential effect of the isotopic substitution on the reactions.