Long Range Corrections to the Vapor-Liquid Equilibrium and Surface Tension of Methane with NVT Molecular Dynamics Simulations

In direct molecular dynamics simulations (MD) of inhomogeneous systems the density is distributed across the interface and, as a result, the conventional long range corrections cannot be used for these systems. In this work, to correct the results of MD simulations for vapor-liquid equilibrium of methane, we have used the slab based corrections to the direction perpendicular to the interface(z-direction) of the force affecting on each particle. All the particles in each slab are considered to have the same coordinate in the z-direction. The density profiles from preliminary simulations with large cut-off distance values were used for the calculation of long range correction terms. New sets of simulation runs, including long range corrections, were then executed with smaller values of cut-off distance. By employing this approach, more accurate results by the cut-off radiusRc=2.5σ in comparison with those produced with the cut-off distance Rc=5.5σ without applying the long range corrections, are observed for the values of the coexisting densities and the surface tension.