Li Peng, Niu Wenxia, Gao Tao, Wang Hongyan
Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, 610065, China.
J Mol Model. 2014 Oct;20(10):2466. doi: 10.1007/s00894-014-2466-3. Epub 2014 Oct 7.
The gas-phase reaction of an Np atom with H2O was investigated using density functional theory and ab initio molecular dynamics. The reaction mechanisms and the corresponding potential energy profiles for different possible spin states were analyzed. Three reaction channels were found in the mechanism study: the isomerization channel, the H2 elimination channel, and the H atom elimination channel. The latter two were observed in the dynamics simulation. It was found that the branching ratio of the title reaction depends on the initial kinetic energy along the transition vector. Product energy distributions for the reaction were evaluated by performing direct classical trajectory calculations on the lowest sextet potential energy surface. The results indicate that most of the available energy appears as the translational energy of the products. The overall results indicate that the H2 elimination channel with low kinetic energy is thermodynamically favored but competes with the H atom elimination channel with higher kinetic energy.
利用密度泛函理论和从头算分子动力学研究了Np原子与H₂O的气相反应。分析了不同可能自旋态的反应机理和相应的势能面。在机理研究中发现了三个反应通道：异构化通道、H₂消除通道和H原子消除通道。后两个通道在动力学模拟中被观测到。发现该反应的分支比取决于沿过渡向量的初始动能。通过在最低六重态势能面上进行直接经典轨迹计算，评估了该反应的产物能量分布。结果表明，大部分可用能量表现为产物的平动能。总体结果表明，低动能的H₂消除通道在热力学上是有利的，但与高动能的H原子消除通道相互竞争。
