Density functional theory for the freezing of charged hard spheres embedded in a uniform neutralizing background

The freezing of equally charged hard spheres embedded in a uniform neutralizing background is investigated theoretically using a recently developed density functional theory. We find a fluid-f.c.c. solid transition which naturally extends the uncharged hard sphere transition studied previously. As in all similar cases investigated hitherto in the literature, the bcc solid has been found to be metastable relative to the fluid. Several possible reasons for this rather surprising result are discussed in detail.