Cavity formation and the drying transition in the Lennard-Jones fluid

By simulation and theory, we study the probability of observing N molecular centers within molecular sized volumes for a Lennard-Jones fluid near liqu id-vapor coexistence. For large volumes and small N, the probability distri bution differs markedly from Gaussian. The free energy per unit surface are a to form empty volumes (i.e., cavities) is a rapidly varying function of t he radius for small cavities. It becomes constant for large volumes. The so urce of these behaviors is the occurrence of drying (i.e., solvent depletio n) at the cavity surface. The crossover to drying occurs on microscopic len gth scales, with significant density depletion found for cavities with radi i of the order of two or more Lennard-Jones diameters. Reasonable agreement is found between the simulation results and the theory developed by Lum, C handler, and Weeks [J. Phys. Chem. B 103, 4570 (1999)].