Gamallo Pablo, Defazio Paolo
Departament de Química Física i IQCT, Universitat de Barcelona, C/Martí i Franquès 1, 08028 Barcelona, Spain.
J Chem Phys. 2009 Jul 28;131(4):044320. doi: 10.1063/1.3190329.
We present the Born-Oppenheimer (BO) and Renner-Teller (RT) coupled-channel dynamics of the N((2)D) + HD --> NH + D and N((2)D) + HD --> ND + H reactions, considering the X (2)A(") and A (2)A(') states and RT and Coriolis couplings. We use the best available potential energy surfaces and obtain initial-state-resolved probabilities, cross sections, and rate constants via the real wave packet and flux methods for both electronic states. In contrast with the RT results of BO-X (2)A(") ones, we point out the role of RT and Coriolis interactions for both reactions and discuss the importance of the excited state on the initial-state-resolved dynamics and on the thermal kinetic rate. Moreover the competition for the formation of two products is discussed, showing some snapshots of the RT wave-packet density on the ground state. However, the BO approximation gives thermal rates that are smaller than those obtained via full RT calculation, especially at 300 K. Our calculated RT rate constants at room temperature are in good agreement with the experimental ones. The branching ratio is also calculated at T = 150-300 K at BO and RT levels. At 300 K the calculated value overestimates slightly the experimental data.
我们展示了N((2)D) + HD --> NH + D和N((2)D) + HD --> ND + H反应的玻恩-奥本海默（BO）和伦纳-泰勒（RT）耦合通道动力学，考虑了X (2)A(")和A (2)A(')态以及RT和科里奥利耦合。我们使用了现有的最佳势能面，并通过实波包和通量方法获得了两个电子态的初态分辨概率、截面和速率常数。与BO-X (2)A(")态的RT结果相反，我们指出了RT和科里奥利相互作用对两个反应的作用，并讨论了激发态对初态分辨动力学和热动力学速率的重要性。此外，还讨论了两种产物形成的竞争，展示了基态上RT波包密度的一些快照。然而，BO近似给出的热速率比通过全RT计算得到的速率小，特别是在300 K时。我们在室温下计算的RT速率常数与实验值吻合良好。还在BO和RT水平下计算了T = 150 - 300 K时的分支比。在300 K时，计算值略微高估了实验数据。
