The Effect Factor of Surface Tension of Liquid/Vapor in Molecular Dynamics Simulation

It is important to select suitable molecular numbers and cut-off radius of interaction potential to study the surface tension between liquid phase and vapor phase by molecular dynamics simulation, which could both save the computer CPU time and reduce the effect of molecular numbers and cut-off radius of interaction potential on calculating results of simulation. The systems of vapor and liquid phase equilibrium, of which molecular numbers are 500,864,1 372 and 2 048,are simulated by selecting Argon as working substance and using Lennard-Jones potential in the rectangle simulation box. It is shown that the simulation result of surface tension is related to simulation molecular numbers. When the molecular numbers exceed 1 000 molecular the simulation result of surface tension tends to constant value. Under the condition of the cut-off radius of potential being equal to 4.5σ, the simulation result of surface tension agrees with experimental value.