title: Density functional approach to thermodynamics of self-assembly.
abstract: A local density functional approximation for predicting the surface crystallization of a thermodynamically small system under gravity is described and tested. Using the model of the classical soft-sphere fluid, the state parameters for such systems are identified. A generalized phase diagram based upon the scaling variables is obtained; systems with the same reduced-state parameters exhibit identical profiles of thermodynamic properties such as density, pressure, and intrinsic chemical potential, measured in the direction of the applied field. The point-thermodynamic approximation of Rowlinson and the local density approximation of the density functional formalism are found to be remarkably accurate. A configurational temperature is defined and shown to agree with the corresponding kinetic temperature for inhomogeneous systems at equilibrium. The structural profiles at the crystal-fluid interface are indicative of a mesolayer of lower density crystal, not seen in the field-free isobaric crystal-liquid interface.
authors.affiliation: Department of Chemistry, UMIST, Manchester M60 1QD.
authors.forename: Radhika S
authors.initials: RS
authors.lastname: Saksena
authors.forename: Leslie V
authors.initials: LV
authors.lastname: Woodcock