Crystal nucleation in the presence of a metastable critical point

Density functional theory is applied to the study of crystal nucleation in the presence of a metastable critical point. A phenomenological model for fluids with short range interactions is developed to study the influence of critical density fluctuations on the structure of the critical nucleus and the height of the barrier to nucleation. Our results show dramatic changes in the nature of crystal nucleation near the metastable critical point, with nucleation rates increasing several orders of magnitude; this behavior has important consequences for nucleation of colloids and proteins from solution. A nonmonotonic dependence of the critical cluster size on supersaturation is observed under these conditions. © 1998 American Institute of Physics. @S0021-9606~98!51325-6#