  The strip projection method is the most important way to generate
quasiperiodic patterns with predefined local structure. We have obtained a very
efficient algorithm for this method which allows one to use it in superspaces
of very high dimension. A version of this algorithm for two-dimensional
clusters and an application to decagonal two-shell clusters (strip projection
in a 10-dimensional superspace) has been presented in math-ph/0504036. The
program in FORTRAN 90 used in this case is very fast (700-800 points are
obtained in 3 minutes).
  We present an application of our algorithm to three-dimensional clusters. The
physical three-dimensional space is embedded into a 31-dimensional superspace
and the strip projection method is used in order to generate a quasiperiodic
packing of interpenetrating translated copies of a three-shell icosahedral
cluster formed by the 12 vertices of a regular icosahedron (the first shell),
the 20 vertices of a regular dodecahedron (the second shell) and the 30
vertices of an icosidodecahedron (the third shell). On a personal computer
Pentium 4 with Fortran PowerStation version 4.0 (Microsoft Developer Studio) we
obtain 400-500 points in 10 minutes.
  More details, bibliography and samples can be found on the website:
http://fpcm5.fizica.unibuc.ro/~ncotfas/
