We perform large-scale simulations of hard regular polygons and determine the nature of the fluid to solid transition and whether there is an intermediate hexatic phase. Hard disks have a first order phase transition from fluid to hexatic and a continuous transition from hexatic to solid [1,2]. As the number of edges goes to infinity, hard regular polygons should behave the same, but different behavior is possible at small edge counts. Million-particle simulations are necessary to relax the finite size effects present in the two-phase region and to compute the quasi-long range translational correlation functions in the hexatic and solid phases. We develop and use HPMC [3,4] to run these simulations on the Titan supercomputer at the OLCF. HPMC is a scalable GPU-accelerated hard particle Monte Carlo simulation engine built on top of HOOMD-blue.
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 J. A. Anderson, M. E. Irrgang, and S. C. Glotzer, preprint