See our article in Journal of Molecular Biology, 5 November 1992, 228, 13-22,
"The interdependence of protein surface topography and bound water molecules
revealed by surface accessibility and fractal density measures", by
Leslie Kuhn, Michael Siani, Michael Pique, Cindy Fisher, Elizabeth Getzoff,
and John Tainer, and the references therein.
All the software of ours mentioned there is now available
for free, sources included, from the Computational Center for Macromolecular
Structure, ccms-help at sdsc.edu.
- Mike Pique