Solidlike phase transitions in a screened Wigner lattice. Statics

Abstract

We generalize the concept of the Wigner lattice by assuming a system where the interaction between particles is proportional to $r^{-1\mathrm{}} \exp (-\lambda r)$, where $r$ is the interparticle distance and ${\lambda }^{-1\mathrm{}}$ the Debye screening length. With Ewald's method we calculate the fractional energy difference between the static bcc and fcc structures. For $\lambda r_s=1.05\mathrm{}$ we predict a phase transition, $r_s$ being the radius of the spherical volume of the unitary cell. Moreover, we compare our results with observations performed on polystyrene spheres in aqueous suspensions.