The potential of mean-force, PMF, in terms of the radial distance, r, between the pair of hydrophobes, is given above for the variable (A) and constant (B) scenarios. Each curve represents a different temperature. The variable case but not the constant case notably exhibits the following trend: with increasing temperature, the wells deepen, especially the one corresponding to binding. The curves are shifted up–down so as to fix the “barrier” at zero energy.