Freezing and melting criteria in non-equilibrium

Using non-equilibrium computer simulations, it is shown that various phenom enological criteria for melting and freezing hold not only in equilibrium b ut in steady-state non-equilibrium as well. In particular, we study the ste ady state of charge-polydisperse. Brownian particles shaken by a time-depen dent oscillatory electric field. Among these criteria are the Lindemann mel ting rule, the Hansen-Verlet freezing rule and the dynamical freezing crite rion proposed for colloidal fluids by Lowen, Palberg and Simon.