Schmitt Sebastian, Fleckenstein Florian, Hasse Hans, Stephan Simon
Laboratory of Engineering Thermodynamics (LTD), RPTU Kaiserslautern, Kaiserslautern 67663, Germany.
J Phys Chem B. 2023 Mar 2;127(8):1789-1802. doi: 10.1021/acs.jpcb.2c07997. Epub 2023 Feb 20.
The prediction of thermophysical properties at extreme conditions is an important application of molecular simulations. The quality of these predictions primarily depends on the quality of the employed force field. In this work, a systematic comparison of classical transferable force fields for the prediction of different thermophysical properties of alkanes at extreme conditions, as they are encountered in tribological applications, was carried out using molecular dynamics simulations. Nine transferable force fields from three different classes were considered (all-atom, united-atom, and coarse-grained force fields). Three linear alkanes (-decane, -icosane, and -triacontane) and two branched alkanes (1-decene trimer and squalane) were studied. Simulations were carried out in a pressure range between 0.1 and 400 MPa at 373.15 K. For each state point, density, viscosity, and self-diffusion coefficient were sampled, and the results were compared to experimental data. The Potoff force field yielded the best results.
极端条件下热物理性质的预测是分子模拟的一项重要应用。这些预测的质量主要取决于所采用力场的质量。在这项工作中，利用分子动力学模拟对用于预测摩擦学应用中遇到的极端条件下烷烃不同热物理性质的经典可转移力场进行了系统比较。考虑了来自三个不同类别的九个可转移力场（全原子、联合原子和粗粒化力场）。研究了三种线性烷烃（癸烷、二十烷和三十烷）和两种支链烷烃（1-癸烯三聚体和角鲨烷）。在373.15 K下于0.1至400 MPa的压力范围内进行模拟。对每个状态点的密度、粘度和自扩散系数进行采样，并将结果与实验数据进行比较。Potoff力场给出了最佳结果。
