We propose a simplified version of the free-energy density functional for the inhomogeneous hard-sphere fluid mixture recently derived by Rosenfeld [Phys. Rev. Lett. 63, 980 (1989)]. This new functional, which requires four distinct weight functions, generates a triplet-direct-correlation function for the one-component fluid, which is in good agreement with Monte Carlo simulation results. It also performs well in describing the density profile of the hard-sphere fluid in contact with hard and soft walls. Yet, it is not suitable for studying the freezing transition.

• Received 30 January 1990

DOI:https://doi.org/10.1103/PhysRevA.42.3382