Although the free energy also contains entropic information, an analogy can be made with the Lennard-Jones potential energies from this study. As mentioned above, the weakening of the Lennard-Jones energies for the HS-W and W-CA cases suggests that more water molecules start interacting with each other than with HS molecules or calcium ions. The point at which the per bead potential energies are strongest, indicating that the interaction sites are saturated with water, is comparable to the x water value obtained by Escalona et al. , at which phase separation occurs. However, the Lennard-Jones potential energies alone do not provide sufficient information about whether or not a phase separation occurred.