Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
J Phys Chem A. 2013 Aug 15;117(32):6940-7. doi: 10.1021/jp310546g. Epub 2012 Dec 14.
The photodissociation of H2O in its B band is a prototype for nonadiabatic reaction dynamics. In addition to dissociation via the adiabatic pathway to the OH(Ã(2)Σ(+)) + H fragments, it also produces the OH(X̃(2)Π) + H fragments through two nonadiabatic pathways: the B̃ → X̃ transition via two conical intersections and the B̃ → Ã transition via a Renner-Teller pair. In this work, the state-to-state dissociation dynamics in all three channels are investigated with a full-dimensional quantum mechanical model using a set of coupled diabatic potential energy surfaces determined at the internally contracted multireference configuration interaction level with the aug-cc-pVQZ basis set. The inclusion of all relevant electronic states not only results in an improved agreement with the latest experimental data but also sheds valuable insights into the competition between the two coexisting nonadiabatic pathways.
H2O 在 B 带中的光解是研究非绝热反应动力学的一个原型。除了通过绝热途径解离为 OH(Ã(2)Σ(+)) + H 碎片外，它还通过两条非绝热途径产生 OH(X̃(2)Π) + H 碎片：通过两个锥形交叉点的 B̃ → X̃跃迁和通过 Renner-Teller 对的 B̃ → Ã 跃迁。在这项工作中，使用一组耦合的非绝热势能面，通过全维量子力学模型研究了所有三个通道中的态态解离动力学，这些势能面是在内部收缩的多参考组态相互作用水平上用 aug-cc-pVQZ 基组确定的。包含所有相关的电子态不仅提高了与最新实验数据的一致性，而且还深入了解了两个共存的非绝热途径之间的竞争。
