space filling sphenoid hendecahedrons - crystal rods
The sphenoid hendecahedron is a space filling polyhedron.
It is special in its low symmetry and creates visually pleasing patterns when rod like sub assemblies are formed.
Considerable credits go to Guy Inchbald who published geometric data and description of these structures here
http://www.steelpillow.com/polyhedra/five_sf/five.htm
2011 William Adams aka WilliamAAdams
published a printable version of the more symmetric
bisymmetric hendecahedron spacefiller
http://www.thingiverse.com/thing:12800