Non-adiabatic quantum reactive scattering in hyperspherical coordinates
Non-adiabatic quantum reactive scattering in hyperspherical coordinates
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DOI：
10.1063/1.5014989
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发表时间：
2018-01-28
影响因子：
4.4
通讯作者：
Kendrick, Brian K.
中科院分区：
文献类型：
--
作者：
Kendrick, Brian K.
本文提出了一种新的电子非绝热量子反应散射方法，它是基于时间无关的耦合通道形式和T Pack和帕克[J. Chem. Phys. 87，3888（1987）]的主轴超球坐标。该方法计算了A + B-2（v，j）AB（v '，j'）+ B和A+ AB（v，j）-> A + AB（v'，j'）反应的全态-态散射矩阵，这些反应涉及两个呈现圆锥相交的耦合电子态。该方法准确地对待所有六个自由度相对于质心，其中包括非零的总角动量J和相同的粒子交换对称性。新的方法被应用到超冷氢交换反应，其中大的几何相效应最近已被报道[B。K. Kendrick等人，物理修订信函115，153201（2015）]。本文报道了碰撞能量在1 μ K ~ 100 K（总能量约为1.9 eV）范围内H/D + HD（v = 4，j = 0）→ H/D + HD（v '，j'）反应的速率系数。基于Boothroyd、Keogh、Martin和Peterson（BKMP 2）和双多体展开加单多项式（DSP）绝热势能面，分别建立了H-3基态和第一激发态的非绝热势能矩阵.使用新的非绝热方法和非绝热势矩阵计算的速率系数重现最近报道的速率，包括几何相位和使用一个单一的绝热基态电子势能面（BKMP 2）计算。几何相位对超冷率的显著增强和抑制以及它对1 K附近几种形状共振的影响得到了证实。这里报道的结果代表了第一个完全非绝热量子反应散射计算的超冷反应，并验证了维格纳阈值行为的几何相位的重要性。(c)2018年作者。
A new electronically non-adiabatic quantum reactive scattering methodology is presented based on a time-independent coupled channel formalism and the adiabatically adjusting principal axis hyperspherical coordinates of T Pack and Parker [J. Chem. Phys. 87, 3888 (1987)]. The methodology computes the full state-to-state scattering matrix for A + B-2(v, j) AB(v', j') + B and A+ AB(v, j) -> A + AB(v' , j') reactions that involve two coupled electronic states which exhibit a conical intersection. The methodology accurately treats all six degrees of freedom relative to the center-of-mass which includes non-zero total angular momentum J and identical particle exchange symmetry. The new methodology is applied to the ultracold hydrogen exchange reaction for which large geometric phase effects have been recently reported [B. K. Kendrick et al., Phys. Rev. Lett. 115, 153201 (2015)]. Rate coefficients for the H/D + HD(v = 4, j = 0) -> H/D + HD(v', j') reactions are reported for collision energies between 1 mu K and 100 K (total energy approximate to 1.9 eV). A new diabatic potential energy matrix is developed based on the Boothroyd, Keogh, Martin, and Peterson (BKMP2) and double many body expansion plus single-polynomial (DSP) adiabatic potential energy surfaces for the ground and first excited electronic states of H-3, respectively. The rate coefficients computed using the new non-adiabatic methodology and diabatic potential matrix reproduce the recently reported rates that include the geometric phase and are computed using a single adiabatic ground electronic state potential energy surface (BKMP2). The dramatic enhancement and suppression of the ultracold rates due to the geometric phase are confirmed as well as its effects on several shape resonances near 1 K. The results reported here represent the first fully non-adiabatic quantum reactive scattering calculation for an ultracold reaction and validate the importance of the geometric phase on the Wigner threshold behavior. (c) 2018 Author(s).