Crystallization and melting in the Lennard-Jones system: Equilibration, relaxation, and long-time dynamics of the moving interface

Nonequilibrium molecular dynamics simulations have been carried out on the growth and melting of the Lennard-Jones (100) interface at small undercooli ngs and superheatings. Two regimes of linear growth rate were discovered: a short-time regime associated with interface relaxation and a long-time reg ime associated with the macroscopic limit of growth and melting. It was sho wn that, if system sizes or equilibration times are taken too small, one wi ll find only the initial regime. On the basis of our very accurate results on the macroscopic growth rates close to equilibrium, the possibility of a discontinuity in the temperature dependence of growth and melting rates at the melting point was ruled out. (C) 2001 American Institute of Physics.