Deiters Ulrich K, Sadus Richard J
Institute for Physical Chemistry, University of Cologne, Greinstr. 4-6, D-50939 Köln, Germany.
Centre for Computational Innovations, Swinburne University of Technology, PO Box 218, Hawthorn, Victoria 3122, Australia.
J Phys Chem B. 2020 Mar 19;124(11):2268-2276. doi: 10.1021/acs.jpcb.9b11108. Epub 2020 Mar 6.
The ability of modern ab initio potentials to predict the thermophysical properties of helium is investigated. A new interatomic potential for helium is reported that is based on the latest available ab initio data and that is much more computationally efficient than other ab initio potentials, without sacrificing accuracy. The role of both two-body and three-body interactions is evaluated using classical Monte Carlo and molecular dynamics simulations. Data are reported for the second virial coefficient, vapor-liquid equilibria, acentric factor, compressibility factor, enthalpy, speed of sound, and isobaric heat capacity. Three-body interactions have a minor influence on the properties of helium with the exception of the estimated critical properties. The influence of quantum particle behavior is relevant at temperatures typically below 200 K. For example, the experimental maximum in the isobaric heat capacities (along isobars) of helium is not observed in the classical simulations and can be attributed to quantum particle behavior. However, above this temperature, helium behaves like a classical fluid and its thermodynamic properties can be adequately predicted by determining only two-body interactions.
研究了现代从头算势预测氦热物理性质的能力。报道了一种新的氦原子间势，它基于最新可得的从头算数据，并且在不牺牲准确性的情况下，计算效率比其他从头算势高得多。使用经典蒙特卡罗和分子动力学模拟评估了两体和三体相互作用的作用。报告了第二维里系数、气液平衡、偏心因子、压缩因子、焓、声速和等压热容的数据。除了估计的临界性质外，三体相互作用对氦的性质影响较小。量子粒子行为的影响在通常低于200 K的温度下是相关的。例如，在经典模拟中未观察到氦等压热容（沿等压线）的实验最大值，这可归因于量子粒子行为。然而，高于此温度时，氦表现得像经典流体，通过仅确定两体相互作用就可以充分预测其热力学性质。
