Fig. 2.

The potential of mean-force, PMF, in terms of the radial distance, r, between the pair of hydrophobes, is given above. The solid curve is obtained through our Monte Carlo simulations utilizing the spherically-symmetric water model. The dotted curves roughly depict the reported results of Ludemann et al.⁴⁶ and Shimizu et al.;⁴⁷ these two employ conventional semi-empirical force-fields for water, SPC⁴⁸ and TIP4P,⁴⁹ respectively. Our PMF has a slightly higher frequency and a moderately lower amplitude. The curves are shifted up–down so as to fix the “barrier” at zero energy.