A mixed order density functional theory for adhesive hard sphere fluid confined between two hard walls

Abstract

The second order direct correlation function of uniform adhesive hard sphere fluid was divided into a hard sphere like part and tail part. Then the density functional formalism based on the universality of the free energy density functional was employed to treat the nonuniform first order direct correlation function for the hard sphere like part, the second order perturbative expansion approximation was employed to treat the tail part for the nonuniform case. The two parts were added together to construct the nonuniform first order direct correlation function of the adhesive hard sphere fluid. Then the ensued result was substituted into the density profile equation in the density functional theory, the density distribution profile predictions from the present method were in good agreement with the corresponding computer simulation data.