  Previously, it has been shown that the direct correlation function for a
Lennard-Jones fluid could be modeled by a sum of that for hard-spheres, a
mean-field tail and a simple linear correction in the core region constructed
so as to reproduce the (known) bulk equation of state of the fluid(Lutsko, JCP
127, 054701 (2007)). Here, this model is combined with ideas from Fundamental
Measure Theory to construct a density functional theory for the free energy.
The theory is shown to accurately describe a range of inhomogeneous conditions
including the liquid-vapor interface, the fluid in contact with a hard wall and
a fluid confined in a slit pore. The theory gives quantitatively accurate
predictions for the surface tension, including its dependence on the potential
cutoff. It also obeys two important exact conditions: that relating the direct
correlation function to the functional derivative of the free energy with
respect to density, and the wall theorem.
