Modeling Collisional Transitions in Thermal Unimolecular Reactions: Successive Trajectories and Two-Dimensional Master Equation for Trifluoromethane Decomposition in an Argon Bath
Modeling Collisional Transitions in Thermal Unimolecular Reactions: Successive Trajectories and Two-Dimensional Master Equation for Trifluoromethane Decomposition in an Argon Bath
复制标题
模拟热单分子反应中的碰撞转变：氩浴中三氟甲烷分解的连续轨迹和二维主方程
DOI：
10.1021/acs.jpca.0c05906
复制
发表时间：
2020
期刊：
影响因子：
2.9
通讯作者：
Akira Matsugi
中科院分区：
文献类型：
--
作者：
Akira Matsugi
用碰撞频率Z和概率分布函数P（E，J;E′，J′）来描述热单分子反应中的碰撞跃迁过程，P（E，J;E′，J′）描述了从由总能量和角动量（E′，J′）指定的初始态到最终态（E，J）的碰撞跃迁概率.本文评价了由ZandP（E，J;E′，J′）组成的碰撞跃迁模型对标题反应的有效性。本模型和它的参数是从经典的轨道模拟计算的转移概率的时刻。该模型明确考虑了能量和角动量转移之间的耦合以及跃迁概率对初始状态的依赖性。该模型的性能进行评估，通过比较求解二维主方程的连续碰撞序列的经典轨迹计算得到的速率常数。速率常数也与现有的实验数据进行了比较。本碰撞过渡模型被发现执行相当不错的预测的压力依赖的速率常数。在预测和速率常数的模型参数的敏感性的不确定性进行了讨论。提出了一个简化版本的模型，它执行以及完整的模型。的简化和强大的程序计算模型参数进行了说明。
Collisional transition processes in thermal unimolecular reactions are modeled by collision frequency,Z, and probability distribution function,P(E,J;E′,J′), which describes the probabilities of collisional transitions from the initial state specified by the total energy and angular momentum, (E′,J′), to the final states, (E,J). The validity of the collisional transition model, consisting ofZandP(E,J;E′,J′), is assessed here for the title reaction. The present model and its parameters are derived from the moments of transition probabilities calculated by classical trajectory simulations. The model explicitly accounts for coupling between the energy and angular momentum transfer and the dependence of transition probability on the initial state. The performance of the model is evaluated by comparing the rate constants calculated by solving the two-dimensional master equation with those obtained from the classical trajectory calculations of the sequence of successive collisions. The rate constants are also compared with available experimental data. The present collisional transition model is found to perform fairly well for predicting the pressure-dependent rate constants. The uncertainty in the prediction and sensitivities of the rate constants to the model parameters are discussed. A simplified version of the model is proposed, which performs as well as the full model. The simplifications and robust procedures for calculating the model parameters are described.