Chen Guangan, Qin Zhi, Li Jing, Liu Linhua
School of Energy and Power Engineering, Shandong University, 250061, Jinan, China.
Optics and Thermal Radiation Research Center, Institute of Frontier and Interdisciplinary Science, Shandong University, 266237, Qingdao, China.
Phys Chem Chem Phys. 2022 Aug 17;24(32):19371-19381. doi: 10.1039/d2cp02690b.
A global potential energy surface (PES) for the electronic ground state of PH(XB) is reported based on accurate energy points and analytically modeled using the combined-hyperbolic-inverse-power-representation (CHIPR) method. A total of 12 339 energy points are calculated by the multireference configuration interaction method with the Davidson correction and extrapolated to the complete basis set limit using the aug-cc-pV(T + d)Z and aug-cc-pV(Q + d)Z basis sets. A switching function is constructed to model the transition between P(D) and P(S) to ensure the reliable behaviors at dissociation limits. The potential energy curves of H(XΣ+g) and PH(XΣ) are refined by a multi-attribute fitting to previous experimental spectroscopic constants. The analytical CHIPR PES reproduces well with the energy points with a root mean square deviation of 41.7 cm. The topographical features of the CHIPR PES are examined and discussed in detail, and they agree well with those of the previous work. The quasi-classical trajectory method is utilized to calculate the integral cross sections and thermal rate constants for the insertion reaction of P(D) + H(XΣ+g) → PH(XΣ) + H(S). The results show a typical characteristic of the endothermic reaction with a barrier and this PES can be a reliable component for constructing the PESs of PH or other larger molecular systems containing PH.
基于精确的能量点,报道了PH(XB)电子基态的全局势能面(PES),并使用组合双曲反幂表示法(CHIPR)进行了分析建模。通过带有戴维森校正的多参考组态相互作用方法计算了总共12339个能量点,并使用aug-cc-pV(T + d)Z和aug-cc-pV(Q + d)Z基组外推到完全基组极限。构建了一个切换函数来模拟P(D)和P(S)之间的跃迁,以确保在解离极限处的可靠行为。通过对先前实验光谱常数的多属性拟合,对H(XΣ+g)和PH(XΣ)的势能曲线进行了优化。解析的CHIPR PES与能量点的拟合效果良好,均方根偏差为41.7 cm。详细研究和讨论了CHIPR PES的地形特征,它们与先前工作的特征吻合良好。利用准经典轨迹方法计算了P(D) + H(XΣ+g) → PH(XΣ) + H(S)插入反应的积分截面和热速率常数。结果显示了具有势垒的吸热反应的典型特征,并且该PES可以作为构建PH或其他包含PH更大分子体系PES的可靠组成部分。