Abstract
Large scale simulations of crystal nucleation from the liquid are performed using the Lennard-Jones potential, to determine the time required for nucleation. By considering both transient and finite-size effects, we successfully predict the nucleation time within order of magnitude without any parameter fitting. All necessary parameters are derived from separate, equilibrium simulations. At smaller undercoolings, large system sizes are required, not only to accommodate large critical nuclei, but also to control statistical effects that are controlled by the density of critical nuclei. Two distinct nucleation regions are observed in the simulations, which are dominated by transient time and steady state nucleation time, respectively. At deep undercoolings, we still show consistency between predicted transient times and simulated nucleation times, which suggests that the short nucleation times in simulations are due to a small barrier to nucleation, rather than spinodal transformation that have been previously predicted. We compare with similar, previous results on a model of Al, which does not show such rapid nucleation at low temperatures, and suggest that the differences are due to the behavior of the reduced barrier G*/kBT.