A PARTITIONED DENSITY-FUNCTIONAL THEORY OF FREEZING - APPLICATION TO SOFT SPHERES

A non-perturbative density functional theory (DFT) for inhomogeneous f luids is developed by partitioning the functional into short range ('e ntropic') and long range ('energetic') contributions. The short range part is treated using standard weighted density functional techniques and the long range contribution is evaluated exactly. This method, whi ch is a generalization of a method due to Likes, C., and Senatore, G., 1995, J. Phys.: Condens. Matter, 7, 6797, does not require the use of a reference system. Results are presented for the calculation of the crystal/fluid phase coexistence for systems interacting with inverse-p ower potentials of the form r(-n), where n = 4, 6 and 12. These result s show that this non-perturbative DFT is capable of predicting the fre ezing of long range inverse power systems (n = 4, 6) into a body-centr ed-cubic lattice. Improvements over earlier methods also are noted in the current results for the solid structure as measured by the Lindema nn ratio.