Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany.
J Chem Phys. 2019 Sep 14;151(10):104106. doi: 10.1063/1.5110246.
The F + CH → HF + CH reaction shows a counter-intuitive mode-selective chemistry and prominent resonances. The prereactive F·CH complex formed in the entrance channel is assumed to play an important role in the dynamics of the reaction. The present work investigates the effect of nonadiabatic transitions and the geometric phase on the low-lying quasibound states of the F·CH complex. Quantum dynamics calculations employing the multiconfigurational time-dependent Hartree approach and accurately accounting for vibronic as well as spin-orbit coupling are performed. Extending previous work [D. Schäpers and U. Manthe, J. Phys. Chem. A 120, 3186 (2016)], which was restricted to the dynamics on a single adiabatic potential energy surface and found the relative rotation of F and CH to proceed almost freely, we found chaotic patterns if vibronic coupling is included. While nonadiabatic transitions strongly affect individual resonances, their effect on averaged quantum state densities and the photodetachment spectrum of F⋅CH is found to be minor.
F + CH → HF + CH 反应表现出一种违反直觉的模式选择性化学和显著的共振。假设在入口通道中形成的预反应 F·CH 配合物在反应动力学中起着重要作用。本工作研究了非绝热跃迁和几何相位对 F·CH 配合物低能准束缚态的影响。采用多组态含时哈特ree 方法进行量子动力学计算，并准确考虑了振子和自旋轨道耦合。扩展了之前仅限于单个绝热势能表面上动力学的工作[D. Schäpers 和 U. Manthe, J. Phys. Chem. A 120, 3186 (2016)]，该工作发现 F 和 CH 的相对旋转几乎是自由的，我们发现如果包含振子耦合，则会出现混沌模式。虽然非绝热跃迁强烈影响单个共振，但它们对平均量子态密度和 F⋅CH 的光解离光谱的影响较小。
