含隧道效应校正和曲率校正的单分子正则速率常数计算及应用  

Calculation and Application for the Tunneling-and-Curvature Involved Thermal Rate Constants

作　　者：冯文林[1] 李宗和[1] 王艳[1] 张绍文[1] 吴俊南[1] 

机构地区：[1]北京师范大学化学系

出　　处：《Chinese Journal of Chemical Physics》1995年第4期302-307,共6页化学物理学报（英文）

基　　金：国家科委基金

摘　　要：本文根据徽正则与正则系综的关系给出了包含隧道效应校正和曲率校正、用积累反应几率表达的单分子反应的正则速率公式ｋ＿ＱＭ（Ｔ），应用自编程序，对氟代乙炔氢迁移反应（Ⅰ）和二氟代乙炔氟迁移反应（Ⅱ）计算了含隧道效应和曲率校正的单分子反应的（ｋ＿ＱＭ（Ｔ）和ｋ＿ＱＭ（Ｔ）／Ａ≠１）。结果表明：隧道效应和曲率校正只在低温（低能）区对氢迁移反应（Ⅰ）的速率常数具有明显的影响，对氟迁移反应（Ⅱ）影响极小；随着温度（或能量）的升高，两者对反应速率常数的影响均不明显。该方法计算的ｋ＿ＱＭ（Ｔ）和ｋ＿ＱＭ（Ｔ）／Ａ≠１的结果分别与采用Ｐｏｌｙｒａｔｅ程序计算的ｋ￣ＣＶＴ／ＭＥＰＳＡＧ（Ｔ）和Ｋ￣ＣＶＴ／ＳＣＳＡＧ（Ｔ）值相接近，但计算要简便，节省机时。Abstract Based on the relationship between microcanonical assembly and canonical assembly,the tunnelingand-curvature involved formula k_QM (T) for the unimolecular thermal rate constants is derived in terms ofthe cunulative reaction probability. The rate constants for the hydrogen transfer reaction in HCCF (Ⅰ) and the fluoro transfer reaction in FCCF (Ⅱ) are calculated by the computational program written by us. The results show that,in low temperature(or low energy), both tunneling and curvature correction have obvious influence on the rate constants only for the reaction (Ⅰ). When the temperature (or energy) increase,the rate constants are less influenced by both effects. Besides the fact that our method saves much calculation and computational time, its results are close to that obtained by Polyrate program.

关 键 词：正则速率常数 隧道效应 曲率效应 氟代乙炔 

分 类 号：O643.11[理学—物理化学] O623.225[理学—化学]