Nucleation for Lennard-Jones Fluid by Density Functional Theory

A non-mean field density functional theory is employed to investigate the vapour--liquid nucleation. The excess Helmholtz free energy functional is formulated in terms of a local density approximation for short ranged repulsion and a density-gradient expansion for long-ranged attractions. An analytical expression for the direct correlation function of a Lennard-Jones fluid is utilized to take into account the effect of long-ranged attractions on intermolecular correlations. With the predicted bulk properties and surface tension as input, the nucleation properties including density profile, work of formation and number of particles at the reduced temperatures T^*=0.694 and 0.741 are investigated. The obtained number of particles in the critical nucleus agrees well with the simulation data.