Schaupp Thomas, Engel Volker
Universität Würzburg Institut für Physikalische und Theoretische Chemie, Emil-Fischer-Str. 42, 97074 Würzburg, Germany.
J Chem Phys. 2019 Aug 28;151(8):084309. doi: 10.1063/1.5111922.
A combined electronic-nuclear wave packet motion is accompanied by temporal changes of probability flux densities. Using a two dimensional model, we study such densities in the vicinity of a conical intersection (CI) between the potential energy surfaces of two electronically excited states. When the dynamics is accompanied by an efficient population transfer, the electronic flux density behaves nearly time-independent although the nuclear flux does not. The second case involves a nuclear motion where the CI is surrounded. There, the nuclear wave packet undergoes a bifurcation, and the electronic density shows characteristics of a rotation. The electronic flux, however, exhibits a constant directional dynamics during the nuclear motion. The geometrical phase which appears in comparing the nuclear dynamics derived from the coupled motion and the Born-Oppenheimer calculation is also seen in the nuclear flux dynamics.
电子-核组合波包运动伴随着概率通量密度的时间变化。我们使用二维模型研究两个电子激发态势能面之间锥形交叉点（CI）附近的此类密度。当动力学伴随着有效的布居转移时，尽管核通量并非如此，但电子通量密度的行为几乎与时间无关。第二种情况涉及围绕CI的核运动。在那里，核波包经历分叉，并且电子密度呈现出旋转特征。然而，在核运动期间，电子通量表现出恒定的方向动力学。在比较由耦合运动和玻恩-奥本海默计算得出的核动力学时出现的几何相位，在核通量动力学中也能看到。
