He Di, Yuan Jiuchuang, Li Huixing, Chen Maodu
Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024, People's Republic of China.
J Chem Phys. 2016 Dec 21;145(23):234312. doi: 10.1063/1.4972229.
A new global potential energy surface (PES) is constructed for the ground state of LiHCl system based on high-quality ab initio energy points calculated using multi-reference configuration interaction calculations with the Davidson correction. The AVQZ and WCVQZ basis sets are employed for H and Li atoms, respectively. To compensate the relativistic effects of heavy element, the AWCVQZ-DK basis set is employed for Cl atom. The neural network method is used for fitting the PES, and the root mean square error is small (1.36 × 10 eV). The spectroscopic constants of the diatoms obtained from the new PES agree well with experimental data. The geometric characteristics of the transition state and the complex are examined and compared with the previous theoretical values. To study the reaction dynamics of the Li(S) + HCl(XΣ) → LiCl(XΣ) + H(S) reaction, quantum reactive scattering dynamics calculations using collection reactant-coordinate-based wave packet method are conducted based on the new PES. The results of the reaction probabilities indicate that a small barrier exists along the reaction path as observed from the PES. The integral cross section curves reveal that the product molecule LiCl is easily excited. In addition, the reaction is dominated by forward scattering, and similar pattern is observed from Becker's experiment.
基于使用含戴维森校正的多参考组态相互作用计算得到的高质量从头算能量点，为LiHCl体系的基态构建了一个新的全局势能面（PES）。H原子和Li原子分别采用AVQZ基组和WCVQZ基组。为补偿重元素的相对论效应，Cl原子采用AWCVQZ-DK基组。采用神经网络方法对PES进行拟合，均方根误差较小（1.36×10 eV）。从新的PES得到的双原子分子的光谱常数与实验数据吻合良好。研究了过渡态和复合物的几何特征，并与先前的理论值进行了比较。为研究Li(S)+HCl(XΣ)→LiCl(XΣ)+H(S)反应的反应动力学，基于新的PES，采用基于收集反应物坐标的波包方法进行了量子反应散射动力学计算。反应概率结果表明，从PES观察到反应路径上存在一个小的势垒。积分截面曲线表明产物分子LiCl很容易被激发。此外，该反应以前向散射为主，这与贝克尔实验中观察到的模式相似。
