NUCLEATION OF LENNARD-JONES FLUIDS - A DENSITY-FUNCTIONAL APPROACH

We have examined the critical nucleus through density functional calcu lations of crystalline fluctuations in a Lennard-Jones fluid. The free energy functional we employ has a square-gradient form, with the para meters for a Lennard-Jones interaction potential determined by a modif ied weighted density approximation applied locally through the Liquid- solid interface. We have found that the interface and the center of th e critical nucleus behave differently at large undercoolings and at la rge superheatings. At large undercoolings, the interface of the critic al nucleus sharpens, in contrast to the critical nucleus near the spin odal (at large superheatings) that is wide in extent and small in ampl itude. We compare the radius and work of formation from classical nucl eation theory to that from density functional calculations. (C) 1996 A merican Institute of Physics.