HOW THE CHOICE OF SHAPE AND ENSEMBLE AFFECT SIMULATIONS OF 2-DIMENSIONAL MELTING

Nonequilibrium quenching in two-dimensional simulations from a solid or liquid to an interfacial-hexatic regime demonstrates the sensitivity of the final results to the shape of the simulation box (final size effect) and to the molecular dynamics ensemble used (constant density versus constant pressure). Even for a small system of N = 1024 particles, under no circumstance is stabilization of the structure factor reached before some nanoseconds. This means that the results given by Naidoo et al. [Mel. Phys. 80, 1 (1993)] using hexatic structure boundaries are too small and pose the question of whether all the published work on two-dimensional melting has used systems that are too small and simulation times that are too short.