How to compute local protein packing density?

[yqdx at vax5.cit.cornell.edu]

  I have a reference by Richards (1974, JMB 82: 1-14) explaining the use of
Voronoi polyhedra to compute local packing density in a protein structure. As
Richards states, there are some problems with the technique.  I am wondering if
anybody knows of any refinements of the technique that take account of
different van der Waals radii, while still prefectly filling space.  Thanks in
advance.
-Chris Bruns
Cornell biochemistry grad student
yqdx at vax5.cit.cornell.edu