Molecular dynamics simulations have been performed on liquid dibromomethane at thermodynamic states corresponding to temperature in the range 268–328 K and pressure varying from 1 bar to 3000 bar. The interaction model is a simple effective two-body pair potential with atom–atom Coulomb and Lennard-Jones interactions and molecules are rigid. Thermodynamic properties have been studied, including the isobaric thermal expansion coefficient, the isothermal compressibility, the heat capacities and the speed of sound. The simulation results exhibit a crossing of the isotherms of the isobaric thermal expansion coefficient at about 800 bar in very good agreement with the prediction of an isothermal fluctuation equation of state predicting such a crossing in the pressure range 650–900 bar, though experimental results up to 1000 bar do not find any crossing.

中文翻译：

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液态二溴甲烷在压力下的计算研究

在液态二溴甲烷的热力学状态下进行了分子动力学模拟，其状态为温度268-328 K，压力从1 bar到3000 bar不等。相互作用模型是一个简单的有效两体对势，具有原子-原子库仑和Lennard-Jones相互作用，并且分子是刚性的。研究了热力学性质，包括等压热膨胀系数，等温可压缩性，热容量和声速。模拟结果显示，等压热膨胀系数的等温线在大约800 bar处相交，这与等温波动状态方程的预测非常吻合，该状态方程预测了在650–900 bar的压力范围内有这种相交，尽管实验结果到1000巴没找到任何穿越。