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Phase diagram of model anisotropic particles with octahedral symmetryEva G. Noya, Carlos Vega, Jonathan P. K. Doye and Ard A. LouisJ. Chem. Phys. 127, 054501 (2007)AbstractWe computed the phase diagram for a system of model anisotropic particles with six attractive patches in an octahedral arrangement. We chose to study this model for a relatively narrow value of the patch width where the lowest-energy configuration of the system is a simple cubic crystal. At this value of the patch width, there is no stable vapour-liquid phase separation, and there are three other crystalline phases in addition to the simple cubic crystal that is most stable at low pressure. Firstly, at moderate pressures, it is more favourable to form a body-centred cubic crystal, which can be viewed as two interpenetrating, and almost non-interacting, simple cubic lattices. Secondly, an orientationally ordered face-centred cubic structure becomes favourable at high pressures and low temperatures. Finally, at high temperatures a face-centred cubic plastic crystal is the most stable solid phase.The full paper is available from JCP Online and arXiv.org. |