Arbelo-González W, Bonnet L, García-Vela A
Max Planck Institut für Kohlenforschung, Mülheim an der Ruhr, Germany.
CNRS, Institut des Sciences Moléculaires, UMR 5255, 33405 Talence, France.
J Chem Phys. 2015 Apr 7;142(13):134111. doi: 10.1063/1.4916646.
The semiclassical Wigner theory (SCWT) of photodissociation dynamics, initially proposed by Brown and Heller [J. Chem. Phys. 75, 186 (1981)] in order to describe state distributions in the products of direct collinear photodissociations, was recently extended to realistic three-dimensional triatomic processes of the same type [Arbelo-González et al., Phys. Chem. Chem. Phys. 15, 9994 (2013)]. The resulting approach, which takes into account rotational motions in addition to vibrational and translational ones, was applied to a triatomic-like model of methyl iodide photodissociation and its predictions were found to be in nearly quantitative agreement with rigorous quantum results, but at a much lower computational cost, making thereby SCWT a potential tool for the study of polyatomic reaction dynamics. Here, we analyse the main reasons for this agreement by means of an elementary model of fragmentation explicitly dealing with the rotational motion only. We show that our formulation of SCWT makes it a semiclassical approximation to an approximate planar quantum treatment of the dynamics, both of sufficient quality for the whole treatment to be satisfying.
光解离动力学的半经典维格纳理论（SCWT）最初由布朗和赫勒 [《化学物理杂志》75, 186 (1981)] 提出，用于描述直接共线光解离产物中的态分布，最近已扩展到相同类型的实际三维三原子过程 [阿韦洛 - 冈萨雷斯等人，《物理化学化学物理》15, 9994 (2013)]。所得方法除了考虑振动和平动外，还考虑了转动运动，该方法被应用于碘甲烷光解离的类三原子模型，发现其预测结果与严格的量子结果几乎在数量上一致，但计算成本要低得多，从而使SCWT成为研究多原子反应动力学的潜在工具。在此，我们通过仅明确处理转动运动的碎片化基本模型来分析这种一致性的主要原因。我们表明，我们对SCWT的表述使其成为对动力学的近似平面量子处理的半经典近似，两者的质量都足以使整个处理令人满意。
