Reply to ‘‘Comment on ‘Prewetting at a solid-fluid interface via Monte Carlo simulation’ ’’

Abstract

Velasco and Tarazona [preceding Comment, Phys. Rev. A 42, 2454 (1990)] have presented density-functional-theory predictions for prewetting at a Lennard-Jones 12-6–9-3 fluid-solid interface and they have compared their results with our recently published Monte Carlo simulation data [J. E. Finn and P. A. Monson, Phys. Rev. A 39, 6402 (1989)]. The agreement is good except for the location of the prewetting line which in the density-functional theory lies at lower values of the pressure relative to saturation than those estimated from the simulations. This leads to prediction of a lower value for the wetting temperature. Velasco and Tarazona suggest that this difference may be due to an underestimation by us of the saturation pressures of the truncated 12-6 fluid. We have performed further Monte Carlo simulations of the coexistence properties of the truncated 12-6 fluid and the results support the accuracy of our method for estimating saturation properties. Thus the difference between simulation and theory cannot be explained in the manner described by Velasco and Tarazona.