Fluid-fluid and fluid-solid transitions in the Kern-Frenkel model from Barker-Henderson thermodynamic perturbation theory

We study the Kern-Frenkel model for patchy colloids using Barker-Henderson second-order thermodynamic perturbation theory. \ud The model describes a fluid where hard sphere particles are decorated with one patch, so that they interact via a square-well (SW) potential if \ud they are sufficiently close one another, and if patches on each particle are properly aligned.\ud Both the gas-liquid and fluid-solid phase coexistences are computed and contrasted against corresponding Monte-Carlo simulations results.\ud We find that the perturbation theory describes rather accurately numerical simulations all the way from a fully covered square-well \ud potential down to the Janus limit (half coverage).\ud In the region where numerical data are not available (from Janus to hard-spheres), the method provides estimates of the location of the critical lines\ud that could serve as a guideline for further efficient numerical work at these low coverages.\ud A comparison with other techniques, such as integral equation theory, highlights the important aspect of this methodology in the present context