Density functional theory of inhomogeneous liquids.I.The liquid-vapor interface in Lennard-Jones fluids

摘要

A simple model is proposed for the direct correlation function(DCF)for simple fluids consisting of a hard-core contribution,a simple parametrized core correction,and a mean-field tail.The model requires as input only the free energy of the homogeneous fluid,obtained,e.g.,from thermodynamic perturbation theory.Comparison to the DCF obtained from simulation of a Lennard-Jones fluid shows this to be a surprisingly good approximation for a wide range of densities.The model is used to construct a density functional theory for inhomogeneous fluids which is applied to the problem of calculating the surface tension of the liquid-vapor interface.The numerical values found are in good agreement with simulation.