We have not completely explored the entire range of values for or at present. Currently, we set the range for such that Å. The parameter is much less sensitive to size, although because this is a kind of mean field theory, there are transition points where the relationship between and (or and hits what resembles a phase transition. As with all mean field results, there is a region of coexistence there, and this can lead to some very interesting physics. For , I have left the following options available with certain restrictions: . Perhaps some negative values exist in some systems when is positive, but the physical meaning of a negative is a bit strange to me. How would you get the two-body term to be repulsive and the three-body term attractive?
An important point to consider is that we cannot have both and . A reasonable guess for the relative magnitude of and is probably , where the means ``absolute value''. Probably values of or are a little extreme. In the future, I hope to add some useful experimental data for solvent-polymer interactions to get a clearer handle of the magnitude of and . I also plan to add some figures to help a little in the explanation here.