Reduced dimensionality quantum dynamics of Cl+CH4 → HCl+CH3 on an ab initio potential

被引:51
作者
Banks, Simon T. [1 ]
Clary, David C. [1 ]
机构
[1] Univ Oxford, Phys & Theoret Chem Dept, Oxford OX1 3QZ, England
关键词
D O I
10.1039/b615460c
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We study the reaction Cl + CH4 -> HCl + CH3 using a 2-D potential energy surface obtained by fitting a double Morse analytical function to high level (CCSD(T)/cc-pVTZ//MP2/cc-pVTZ) ab initio data. Dynamics simulations are performed in hyperspherical coordinates with the close-coupled equations being solved using R-matrix propagation. Quantum contributions from spectator modes are included via a harmonic zero-point correction to the ab initio data prior to fitting the potential. This is the first time this method has been applied to a heavy-light-heavy reaction and the first time it has been used to study differential cross sections. We find thermal rate constants and state-to-state differential cross sections which are in good agreement with experimental data. We discuss the applicability of our method to the study of kinetic isotope effects (KIEs), which we derive for the CH4/CD4 substitution. The calculated KIE compares favourably with experiment. Finally, we discuss the sensitivity of the results of dynamics simulations on the accuracy of the fitted potential.
引用
收藏
页码:933 / 943
页数:11
相关论文
共 64 条
[1]  
Bowman J. M., 1985, THEORY CHEM REACTION, P47
[2]  
Bowman J. M., 2000, REACTION MOL DYNAMIC
[3]   INCORPORATION OF COLLINEAR EXACT QUANTUM REACTION PROBABILITIES INTO 3-DIMENSIONAL TRANSITION-STATE THEORY [J].
BOWMAN, JM ;
JU, GZ ;
LEE, KT .
JOURNAL OF PHYSICAL CHEMISTRY, 1982, 86 (12) :2232-2239
[4]   REDUCED DIMENSIONALITY THEORIES OF QUANTUM REACTIVE SCATTERING [J].
BOWMAN, JM .
ADVANCES IN CHEMICAL PHYSICS, 1985, 61 :115-167
[5]   APPLICATION OF HYPERSPHERICAL COORDINATES TO 4-ATOM REACTIVE SCATTERING - H-2+CN-]H+HCN [J].
BROOKS, AN ;
CLARY, DC .
JOURNAL OF CHEMICAL PHYSICS, 1990, 92 (07) :4178-4190
[6]   Kinetics of reactions of Cl atoms with methane and chlorinated methanes [J].
Bryukov, MG ;
Slagle, IR ;
Knyazev, VD .
JOURNAL OF PHYSICAL CHEMISTRY A, 2002, 106 (44) :10532-10542
[7]   KINETIC ISOTOPE EFFECT IN PHOTOCHLORINATION OF H2, CH4, CHCL3, AND C2H6 [J].
CHILTZ, G ;
JOHNSTON, HS ;
HUYBRECHTS, G ;
GOLDFINGER, P ;
MEYERS, L ;
VERBEKE, G ;
ECKLING, R .
JOURNAL OF CHEMICAL PHYSICS, 1963, 38 (05) :1053-&
[8]   Quantum dynamics of the O(3P)+CH4→CH3+OH reaction [J].
Clary, DC .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 1999, 1 (06) :1173-1179
[9]   QUANTUM REACTIVE SCATTERING OF 4-ATOM REACTIONS WITH NONLINEAR GEOMETRY - OH+H-2-]H2O+H [J].
CLARY, DC .
JOURNAL OF CHEMICAL PHYSICS, 1991, 95 (10) :7298-7310
[10]  
Clyne M. A., 1973, J CHEM SOC F1, V69, P1547, DOI [10.1039/f19736901547, DOI 10.1039/F19736901547]