Institut für Chemie, Universität Rostock, 18059 Rostock, Germany.
J Chem Phys. 2017 Mar 21;146(11):114304. doi: 10.1063/1.4978412.
A six-dimensional potential energy surface (PES) for the interaction of two rigid propane molecules was determined from supermolecular ab initio calculations up to the coupled cluster with single, double, and perturbative triple excitations level of theory for 9452 configurations. An analytical site-site potential function with 14 sites per molecule was fitted to the calculated interaction energies. To validate the analytical PES, the second virial coefficient and the dilute gas shear viscosity and thermal conductivity of propane were computed. The dispersion part of the potential function was slightly adjusted such that quantitative agreement with the most accurate experimental data for the second virial coefficient at room temperature was achieved. The adjusted PES yields values for the three properties that are in very good agreement with the best experimental data at all temperatures.
从超级分子从头计算到耦合簇单、双和微扰三激发水平理论，确定了两个刚性丙烷分子相互作用的六维势能面（PES），共计算了 9452 种构型。拟合了具有每个分子 14 个位点的分析位点-位点势能函数，以计算相互作用能。为了验证分析 PES，计算了丙烷的第二维里系数以及稀气体剪切黏度和热导率。对势能函数的色散部分进行了微调，以使在室温下与第二维里系数的最准确实验数据达到定量一致。调整后的 PES 对这三个性质的值与所有温度下的最佳实验数据非常吻合。
