反应物分子初始振动激发对N(~4S)+H_2→NH+H立体动力学性质的影响

Effect of reagent vibrational excitation on stereodynamical properties of N(~4S)+H_2→NH+H reaction

在高精度从头计算DMBE势能面上运用准经典轨线方法讨论反应物分子初始振动激发对N(4S)+H2→NH+H反应的立体动力学性质的影响,同时对反应几率、反应截面进行研究。结果表明:产物的转动角动量j'在垂直于反应物相对速度矢量k的方向上的排列取向程度在高振动态时随着初始反应物振动量子数的增加而减小;二面角分布函数P(φr)显示产物的转动角动量,有比较强的定向效应,随着初始振动量子数的增加呈现出减小的趋势;反应物分子的初始振动激发对产物分子的转动排列取向效应和定向效应等立体动力学性质产生很大影响。

The effect of reagent vibrational excitation on the stereodynamical properties of N （4S）＋H2→NH＋H reaction was investigated by quasi-classical trajectory （QCT） method on the highly accurate 4A＂ double many-body expansion （DMBE） potential energy surface （PES）. And the reaction probability and the reaction cross-section were also studied. The results show that the alignment of the product rotational angular momentum j＇ along the perpendicular direction to relative velocity vector k decreases with the vibrational quantum number increasing. The dihedral angle distribution function P（φr） shows the rotational angular momentum of the product and has relatively strong orientation effect, which decreases with initial vibrational quantum number increasing. The vibrational excitation of the reagent has a considerable influence on the stereodynamical properties of alignment effect and orientation effect of product rotational angular momentum.