2008/11/30 by Josep C. Pàmies, Angelo Cacciuto, Daan Frenkel · 1 citation
Physics and Astronomy · #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1063/1.3186742
published as J. Chem. Phys. 131, 044514 (2009) · The inset in Fig. 4 in the previous version had incorrect ordinate values. This has been corrected here. This mistake does not affect the remaining content of the article
arxiv created 2009/10/20 · arxiv updated 2009/12/01
We report the phase diagram of interpenetrating Hertzian spheres. The Hertz potential is purely repulsive, bounded at zero separation, and decreases monotonically as a power law with exponent 5/2, vanishing at the overlapping threshold. This simple functional describes the elastic interaction of weakly deformable bodies and, therefore, it is a reliable physical model of soft macromolecules, like star polymers and globular micelles. Using thermodynamic integration and extensive Monte Carlo simulations, we computed accurate free energies of the fluid phase and a large number of crystal structures. For this, we defined a general primitive unit cell that allows for the simulation of any lattice. We found multiple re-entrant melting and first-order transitions between crystals with cubic, trigonal, tetragonal, and hexagonal symmetries.