A molecular dynamics investigation of microscopic characteristics and stress properties of the liquid-vapor equilibrium interface

The molecular behaviors of saturated liquid-vapor equilibrium system are simulated by molecular dynamics simulations of Verlet-List method and dynamic storage. The microscopic physical characteristics, stress properties and influence of temperature change on thermodynamic properties of liquid-vapor interface are studied. The results show that: the liquid-vapor interface fluctuates up and down in both space and time at a unsteady state and the transition of molecules from liquid to gas is a mutation process; the thickness of liquid-vapor transition zone is the same as the width of partial interfacial fluctuation zone and it is verified that the liquid-vapor transition zone and the interfacial fluctuation zone are consistent; when the temperature changes from 0.7 to 1.1, the thickness of liquid-vapor interface increases from 4 to 9.5 though surface tension and two-phase density difference are constantly reducing; when temperature close to critical temperature, the surface tension of the system tends to 0.