用变分过渡态理论研究NH_3+NH→2NH_2反应动力学  

Dynamic Theoretical Studies with the Variational Transitional state Theory:NH 3+NH(X 3∑)→2NH 2 Reaction

作　　者：尹鸿鸣[1,2] 刘传朴[1,2] 张晓平[1,2] 郭敬忠[1,2] 顾月姝[1,2] 居冠之[1,2] 

机构地区：[1]山东大学化学院 [2]南京大学化学系

出　　处：《分子科学学报》1998年第4期36-40,共5页Journal of Molecular Science

基　　金：国家教委博士点基金

摘　　要：利用变分过渡态理论的“直接动力学”方法对ＮＨ３分子和基态ＮＨ（Ｘ３∑）自由基的反应进行了理论研究；利用从头算计算得到反应体系的电子结构能和能量梯度等信息，计算了２００～２５００Ｋ温度范围该反应的速率常数和穿透系数，分析了影响隧道效应和反应速率常数的一些因素．结果表明，在低温情况下，变分对于此反应影响较大，隧道效应特别明显．计算得到的速率常数和实验值符合得很好．In this paper,the reaction of NH 3 molecule and ground state NH radical is studied by the “direct dynamics” method of variational transition state theory,which uses the information on electronic structure energy and energy derivatives calculated ab initio along the minium energy path. The rate constants and transmission coefficients were calculated for the temperature range 200～2 500 K,It analyzes several factors that affect the tunneling effect and rate constant. The result indicates that, in the case of low temperature, the variational effect is large to this reaction,the tunneling effect is very obvious. The rate constants calculated are match to the experiment value well.

关 键 词：变分过渡态 隧道效应 速率常数 

分 类 号：O641.121[理学—物理化学]