Deiters Ulrich K, Sadus Richard J
Institute of Physical Chemistry, University of Cologne, Luxemburger Str. 116, D-50939 Köln, Germany.
Centre for Computational Innovations, Swinburne University of Technology, P.O. Box 218, Hawthorn, Victoria 3122, Australia.
J Chem Phys. 2019 Jul 21;151(3):034509. doi: 10.1063/1.5109052.
Fully a priori predictions are reported for the vapor-liquid equilibria (VLE) properties of Ar, Kr, and Xe using molecular simulation techniques and recently developed ab initio two-body interatomic potentials. Simulation data are reported at temperatures from near the triple point to close to the critical point. The two-body ab initio potentials exaggerate the size of the experimental VLE temperature-density envelope, overestimating the critical temperature and underestimating the vapor pressure. These deficiencies can be partially rectified by the addition of a density-dependent three-body term. At many temperatures, the ab initio + three-body simulations for Kr and Xe predict the vapor pressure to an accuracy that is close to experimental uncertainty. The predicted VLE coexisting densities for Xe almost match experimental data. The improvement with experiment is also reflected in more accurate enthalpies of vaporization. The fully a priori predictions for all of the VLE properties of either Kr or Xe are noticeably superior to simulations using the Lennard-Jones potential.
利用分子模拟技术和最近开发的从头算二体原子间势，报告了对氩、氪和氙的气液平衡（VLE）性质的完全先验预测。在从接近三相点到接近临界点的温度下报告了模拟数据。二体从头算势夸大了实验VLE温度-密度包络的大小，高估了临界温度并低估了蒸气压。通过添加密度依赖的三体项，可以部分纠正这些不足。在许多温度下，氪和氙的从头算+三体模拟预测蒸气压的精度接近实验不确定性。预测的氙的VLE共存密度几乎与实验数据匹配。与实验的改进也体现在更准确的汽化焓上。氪或氙的所有VLE性质的完全先验预测明显优于使用 Lennard-Jones 势的模拟。
