Analysis of the intermolecular potential of Ar–CH4: An ab initio study
Analysis of the intermolecular potential of Ar–CH4: An ab initio study
复制标题
Ar-CH4 分子间势分析：从头算研究
DOI：
10.1063/1.462482
复制
发表时间：
1992
影响因子：
4.4
通讯作者：
S. M. Cybulski
中科院分区：
文献类型：
--
作者：
M. Szczęśniak;G. Chal;asiński;S. M. Cybulski
本文应用分子间力的微扰理论和超分子Mo/ller-Plesset处理方法分析了Ar-CH_4体系的势能面。Ar-CH_4势能面的各向异性主要是由于交换排斥。在平衡结构中，Ar接近CH 4四面体的面，从而避免与C-H键接触。发现平衡Ar-C分离等于7.5 a0，De能量为113 cm−1。我们估计，我们的De可能太小，相对于准确值最多可小25%。Ar-CH 4的性质也与其他Ar-分子系统，如Ar-NH 3，Ar-H 2 O和Ar-HCl进行了比较。我们发现，弱质子供体绑定到Ar（CH 4，NH 3）的平衡结构是由交换排斥，而那些有效的质子供体，如HCl（和在较小程度上的H2O），从Ar的强极化在一个分子的字段的结果。
The perturbation theory of intermolecular forces in conjunction with the supermolecular Mo/ller–Plesset treatment is applied in the analysis of the potential energy surface of Ar–CH4. The anisotropy of the Ar–CH4 potential energy surface is chiefly due to exchange repulsion. In the equilibrium structure, Ar approaches the face of CH4 tetrahedron thus avoiding contacts with C–H bonds. The equilibrium Ar–C separation was found equal to 7.5 a0 and the De energy to 113 cm−1. We estimate that our De may be too small by up to 25% with respect to the accurate value. The properties of Ar–CH4 are also compared with other Ar‐molecule systems, such as Ar–NH3, Ar–H2O, and Ar–HCl. We find that the equilibrium structures of weak proton donors bound to Ar (CH4, NH3) are determined by the exchange repulsion, while those of efficient proton donors, such as HCl (and to a lesser extent H2O), result from the strong polarization of Ar in the field of a molecule.