HeH_2~＋体系的势能函数与动力学研究（二）He＋H_2~＋（V）与HeH~＋

POTENTIAL ENERGY FUNCTION AND REACTION DYNAMICS FOR HeH_2￣+ SYSTEM (Ⅱ) THE CALCULATION OF REACTION CROSS SECTIONFOR He+H_2￣+ (V) AND HeH￣+ (V= 0)+H

基于多体项展式方法所导出的ＨｅＨ（２∑＋）的分析势能函数［８］，用准经典的Ｍｏｎｔｅｃａｒｌｏ轨迹法研究了Ｈｅ＋Ｈ（Ｖ）→ＨｅＨ＋＋Ｈ、Ｈｅ＋Ｈ（Ｖ）→Ｈｅ＋Ｈ＋Ｈ＋和ＨｅＨ＋＋Ｈ→Ｈ＋Ｈｅ的反应动力学。研究结果指出，前两个反应在Ｈ的初始振动基态时的反应阈能分别为２０ｋｃａｌ·ｍｏｌ－１和６５ｋｃａｌ·ｍｏｌ－１，反应阈能随振动量子数增大而减小。最后一个反应是无阈能的。

The reaction dynamics for He+H (V)→HeH+ +H,He+H (V)→He+H+H+ and HeH+ + H →H +He have been studied based on the Potential energy function of HeH (2∑+ )[8]. It is shown that the threshold energy for the first and second reactions, at the vibrational ground state of H, are 20 kcal· mol-1 and 65 kcal· mol-1, respectively. The threshold energy decreases with the vibration level of H. The third one is a reaction without threshold energy.