Laboratory of Theoretical Physical Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
J Chem Phys. 2012 Dec 14;137(22):22A516. doi: 10.1063/1.4738878.
We propose to measure the importance of spin-orbit couplings (SOCs) in the nonadiabatic molecular quantum dynamics rigorously with quantum fidelity. To make the criterion practical, quantum fidelity is estimated efficiently with the multiple-surface dephasing representation (MSDR). The MSDR is a semiclassical method that includes nuclear quantum effects through interference of mixed quantum-classical trajectories without the need for the Hessian of potential energy surfaces. Two variants of the MSDR are studied, in which the nuclei are propagated either with the fewest-switches surface hopping or with the locally mean field dynamics. The fidelity criterion and MSDR are first tested on one-dimensional model systems amenable to numerically exact quantum dynamics. Then, the MSDR is combined with "on-the-fly" computed electronic structure to measure the importance of SOCs and nonadiabatic couplings in the photoisomerization dynamics of CH(2)NH(2)(+) considering 20 electronic states and in the collision of F + H(2) considering six electronic states.
我们提议通过量子保真度来严格地衡量自旋轨道耦合（SOCs）在非绝热分子量子动力学中的重要性。为了使该标准具有实际意义，通过多表面退相表示（MSDR）有效地估计量子保真度。MSDR 是一种半经典方法，通过混合量子经典轨迹的干涉来包含核量子效应，而无需势能面的 Hessian。研究了 MSDR 的两种变体，其中核的传播要么采用最少切换的表面跳跃，要么采用局部平均场动力学。保真度标准和 MSDR 首先在一维模型系统上进行了测试，这些系统可以进行数值精确的量子动力学计算。然后，将 MSDR 与“实时”计算的电子结构相结合，以衡量 SOCs 和非绝热耦合在 CH(2)NH(2)(+)光异构化动力学中的重要性，考虑了 20 个电子态，以及在 F + H(2)碰撞中考虑了六个电子态。
