采用量子波包方法和准经典轨线方法研究S(^3P)＋HD反应

Quantum wave-packet and quasiclassical tra jectory of reaction S（^3P）＋HD

利用量子波包方法和准经典轨线方法在一个新的3A′′势能面上研究了S(3P)+HD→SD+H和SH+D反应的动力学性质.计算得到了两个反应通道在碰撞能为0.8—2.2 eV范围内的J=0反应几率、积分反应截面、内同位素因子和产物转动取向因子.这些结果揭示了S(3P)+HD反应非常明显的内同位素效应.通过对势能面和反应轨线的分析,我们发现了SD+H反应通道一个新的反应机制.S(3P)+HD反应的内同位素效应可以利用新发现的反应机制和反应的质量组合来进行解释.

In this paper, the S（^3P ）＋HD→SD＋H and SH＋D reactions are studied by means of quantum wave packet （QMWP） and quasi-classical trajectory （QCT） methods on a new ab initio ^3A′′potential energy surface. The reactive probabilities, integral cross sections, intra-molecular isotope parameters and product rotational alignment parameters for both reactive channels are calculated for collision energies in a range between 0.8 and 2.2 eV. The results reveal a pronounced isotopic effect. Plots of the potential energy surface and typical reactive trajectories show the evidence of an additional reaction mechanism for the SD＋H product channel. This reaction mechanism, together with mass combination, can explain the isotopic effect for the title reaction.