Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan.
J Chem Phys. 2013 Nov 21;139(19):194501. doi: 10.1063/1.4829760.
We have calculated the intermolecular interaction energies of the chloroform dimer in 12 orientations using the second-order Møller-Plesset perturbation theory. Single point energies of important geometries were calibrated by the coupled cluster with single and double and perturbative triple excitation method. Dunning's correlation consistent basis sets up to aug-cc-pVQZ have been employed in extrapolating the interaction energies to the complete basis set limit values. With the ab initio potential data we constructed a 5-site force field model for molecular dynamics simulations. We compared the simulation results with recent experiments and obtained quantitative agreements for the detailed atomwise radial distribution functions. Our results were also consistent with previous results using empirical force fields with polarization effects. Moreover, the calculated diffusion coefficients reproduced the experimental data over a wide range of thermodynamic conditions. To the best of our knowledge, this is the first ab initio force field which is capable of competing with existing empirical force fields for liquid chloroform.
我们使用二级 Møller-Plesset 微扰理论计算了 12 种构象下氯仿二聚体的分子间相互作用能。通过耦合簇单双加扰动三激发方法对重要构象的单点能进行了校准。Dunning 的相关一致基组扩展到 aug-cc-pVQZ 被用于将相互作用能外推到完全基组极限值。利用从头算势能数据，我们构建了一个用于分子动力学模拟的 5 位点力场模型。我们将模拟结果与最近的实验进行了比较，对于详细的原子径向分布函数，我们得到了定量的一致。我们的结果与以前使用具有极化效应的经验力场的结果也是一致的。此外，计算得到的扩散系数在很宽的热力学条件范围内再现了实验数据。据我们所知，这是第一个能够与现有经验力场竞争的用于液态氯仿的从头算力场。
