Smolin Andrey G, Vasyutinskii Oleg S, Balint-Kurti Gabriel G, Brown Alex
Ioffe Physico-Technical Institute Russian Academy of Sciences, 194021 St.-Petersburg, Russia.
J Phys Chem A. 2006 Apr 27;110(16):5371-8. doi: 10.1021/jp0562429.
Ab initio potential energy curves, transition dipole moments, and spin-orbit coupling matrix elements are computed for HBr. These are then used, within the framework of time-dependent quantum-mechanical wave-packet calculations, to study the photodissociation dynamics of the molecule. Total and partial integral cross sections, the branching fraction for the formation of excited-state bromine atoms Br(2P(1/2)), and the lowest order anisotropy parameters, beta, for both ground and excited-state bromine are calculated as a function of photolysis energy and compared to experimental and theoretical data determined previously. Higher order anisotropy parameters are computed for the first time for HBr and compared to recent experimental measurements. A new expression for the Re[a1(3) (parallel, perpendicular)] parameter describing coherent parallel and perpendicular production of ground-state bromine in terms of the dynamical functions is given. Although good agreement is obtained between the theoretical predictions and the experimental measurements, the discrepancies are analyzed to establish how improvements might be achieved. Insight is obtained into the nonadiabatic dynamics by comparing the results of diabatic and fully adiabatic calculations.
计算了HBr的从头算势能曲线、跃迁偶极矩和自旋轨道耦合矩阵元。然后，在含时量子力学波包计算的框架内，利用这些结果研究了该分子的光解离动力学。计算了总积分截面和部分积分截面、激发态溴原子Br(2P(1/2))形成的分支比，以及基态和激发态溴的最低阶各向异性参数β，并将其作为光解能量的函数进行计算，并与先前确定的实验和理论数据进行比较。首次计算了HBr的高阶各向异性参数，并与最近的实验测量结果进行了比较。给出了一个新的表达式，用动力学函数描述了基态溴的相干平行和垂直产生的Re[a1(3) (平行, 垂直)]参数。虽然理论预测与实验测量结果取得了较好的一致性，但仍对差异进行了分析，以确定如何实现改进。通过比较非绝热和完全绝热计算的结果，深入了解了非绝热动力学。
