Li Zheng, Xie Daiqian, Sun Zhigang, Zhang Dong H, Lin Shi Ying, Guo Hua
Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
J Chem Phys. 2009 Sep 28;131(12):124313. doi: 10.1063/1.3241134.
Quantum state-to-state dynamics for the NH + H/D --> H + NH/ND exchange reaction is reported on an accurate ab initio potential energy surface. The differential cross section is dominated by scattering into both the forward and backward directions, while the product shows strong rotational excitation. The calculated rate constant for the NH + D reaction is in excellent agreement with experiment. The applicability of a quantum statistical model is tested against exact state-to-state quantum results. Due to strong nonreactive scattering, the statistical model significantly overestimates the integral cross section. However, it is shown that the product state distribution and differential cross sections are reasonably well reproduced by the statistical model because the reactive scattering is dominated by a complex-forming mechanism.
报道了在精确的从头算势能面上，NH + H/D → H + NH/ND 交换反应的量子态到态动力学。微分截面主要由向前和向后方向的散射主导，而产物显示出强烈的转动激发。计算得到的 NH + D 反应速率常数与实验结果非常吻合。针对精确的态到态量子结果测试了量子统计模型的适用性。由于强烈的非反应性散射，统计模型显著高估了积分截面。然而，结果表明，统计模型能够较好地再现产物态分布和微分截面，因为反应性散射主要由形成复合物的机制主导。
