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Regular version of the site

Article

Comparison of forcefields for molecular dynamics simulations of hydrocarbon phase diagrams

Journal of Physics: Conference Series. 2018. Vol. 946. P. 012100-1-012100-6.
Pisarev V., Zakharov S. A.

Molecular dynamics calculations are performed to calculate vapor–liquid equilibrium of methane–n-butane mixture. Three force-field models are tested: the TraPPE-UA united-atom forcefield, LOPLS-AA all-atom forcefield and a fully flexible version of the TraPPEEH all-atom forcefield. All those forcefields reproduce well the composition of liquid phase in the mixture as a function of pressure at the 300 K isotherm, while significant discrepancies from experimental data are observed in the saturated vapor compositions with OPLS-AA and TraPPE-UA forcefields. The best agreement with the experimental phase diagram is found with TraPPE-EH forcefield which accurately reproduces compositions of both liquid and vapor phase. This forcefield can be recommended for simulation of two-phase hydrocarbon systems.