Simulation of the chemical potential and the cavity free energy of dense hard-sphere fluids

The chemical potential of dense hard-sphere fluids, and also the work of cavity formation, are simulated directly by a force-balance Monte Carlo technique. Here the coupling between a solute and the solvent varies in the presence of an external field. For a hard-sphere fluid the variable is the cavity diameter, and the scaled particle theory proves sufficient for the applied field. The method is shown to be viable for densities as high as the freezing transition. A vectorizable Monte Carlo computer algorithm is also given.