First-Principles Theory for the H + CH4 → H2 + CH3 Reaction
First-Principles Theory for the H + CH4 → H2 + CH3 Reaction
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DOI：
10.1126/science.1104085
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发表时间：
2004-12
期刊：
影响因子：
56.9
通讯作者：
Tao Wu;H. Werner;U. Manthe
中科院分区：
文献类型：
--
作者：
Tao Wu;H. Werner;U. Manthe
报道了氢原子与甲烷在精确的从头势能表面上反应的全维量子动力学模拟。基于第一性原理理论，热速率常数的预测精度可与（甚至超过）实验精度相媲美。理论预测在不同组报告的显着变化的实验速率常数的范围内。以前只有较小的三或四原子反应系统才能达到这种精度水平。与经典过渡态理论的比较证实了量子力学隧道效应对于低于 400 开尔文的速率常数的重要性。
A full-dimensional quantum dynamics simulation of a hydrogen atom reacting with methane on an accurate ab initio potential energy surface is reported. Based on first-principles theory, thermal rate constants are predicted with an accuracy comparable to (or even exceeding) experimental precision. The theoretical prediction is within the range of the significantly varied experimental rate constants reported by different groups. This level of accuracy has previously been achieved only for smaller, three-or four-atom reactive systems. Comparison with classical transition state theory confirms the importance of quantum mechanical tunneling for the rate constant below 400 kelvin.