Zhao Bin, Manthe Uwe
Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany.
J Chem Phys. 2020 Jun 21;152(23):231102. doi: 10.1063/5.0013852.
Reactions of methane with different atoms are benchmark examples of elementary reaction processes intensively studied by theory and experiment. Due to the presence of conical intersections and spin-orbit coupling, non-adiabatic transitions can occur in reactions with F, Cl, or O atoms. Extending detailed quantum theory beyond the Born-Oppenheimer approximation for polyatomic reaction processes, non-adiabatic wave packet dynamics calculations studying the F(P)/F(P) + CHD → HF + CD reaction on accurate vibronically and spin-orbit coupled diabatic potential energy surfaces are presented. Non-adiabatic transitions are found to increase the reactivity compared to Born-Oppenheimer theory and are more prominent than in triatomic reactions previously studied. Furthermore, the lifetimes of reactive resonances are reduced. The reactivity of F(P) is found to exceed the one of F(P) even at low collision energies.
甲烷与不同原子的反应是理论和实验深入研究的基本反应过程的基准示例。由于存在锥形交叉点和自旋轨道耦合，与F、Cl或O原子的反应中会发生非绝热跃迁。本文提出了超越多原子反应过程的玻恩-奥本海默近似的详细量子理论，在精确的振转和自旋轨道耦合的非绝热势能面上研究F(P)/F(P)+CHD→HF+CD反应的非绝热波包动力学计算。发现非绝热跃迁与玻恩-奥本海默理论相比增加了反应活性，并且比先前研究的三原子反应中更显著。此外，反应共振的寿命缩短。发现即使在低碰撞能量下，F(P)的反应活性也超过F(P)。
