Lattice-switch Monte Carlo simulation for binary hard-sphere crystals.
We show how to generalize the lattice-switch Monte Carlo method to calculate the phase diagram of a binary system. A global coordinate transformation is combined with a modification of particle diameters, enabling the multicomponent system in question to be explored and directly compared to a suitable reference state in a single Monte Carlo simulation. We use the method to evaluate the free energies of binary hard-sphere crystals. Calculations at moderate size ratios alpha=0.58 and 0.73 are in agreement with previous results, and confirm AB2 and AB13 as stable structures. We also find that the AB(CsCl) structure is not entropically stable at the size ratio and volume where it has been reported experimentally, and therefore that those observations cannot be explained by packing effects alone.
Jackson
A N
AN
SUPA, School of Physics, University of Edinburgh, Scotland, United Kingdom.
Ackland
G J
GJ