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.