Christoffel Kurt M, Jin Zhong, Braams Bastiaan J, Bowman Joel M
Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, 1521 Dickey Drive, Emory University, Atlanta, Georgia 30322, USA.
J Phys Chem A. 2007 Jul 26;111(29):6658-64. doi: 10.1021/jp068722l. Epub 2007 Mar 13.
A full dimensional ab initio potential energy surface for the CH5+ system based on coupled cluster electronic structure calculations and capable of describing the dissociation of methonium ion into methyl cation and molecular hydrogen (J. Phys. Chem. A 2006, 110, 1569) is used in quasiclassical trajectory calculations of the reaction CH3++HD-->CH2D++H2 for low collision energies of relevance to astrochemistry. Cross sections for the exchange are obtained at several relative translational energies and a fit to the energy dependence of the cross sections is used to obtain the rate constant at temperatures between 10 and 50 K. The calculated rate constant at 10 K agrees well with the previously reported experimental value. Internal energy distributions of the products are presented and discussed in the context of zero-point energy "noncompliance".
基于耦合簇电子结构计算且能够描述鎓离子分解为甲基阳离子和分子氢的CH5+体系的全维从头算势能面（《物理化学杂志A》2006年，第110卷，第1569页），被用于与天体化学相关的低碰撞能量下CH3++HD→CH2D++H2反应的准经典轨迹计算。在几个相对平动能量下获得了交换截面，并对截面的能量依赖性进行拟合，以得到10至50 K温度范围内的速率常数。在10 K时计算得到的速率常数与先前报道的实验值吻合良好。给出了产物的内能分布，并在零点能量“不相符”的背景下进行了讨论。
