FCC Bridged Tetraspheres

The pieces of this puzzle are generated with the FCC (face-centered cubic) Sphere packing lattice. In that lattice, each sphere has twelve immediate neighbors, which touch it, and six next-nearest neighbors which can be reached by making small bridges between the spheres. Every possible shape made up of four spheres connected in these ways is represented. There are 81 pieces total, which can be divided into planar and non-planar sets, one with a 8x8 base and the other with a 7x7 base, similar to the tetrarhons. Each set can make a square pyramid, or together they can make an octahedron. many other shapes are also possible, More info on this can be found at www.polyforms.eu Have fun!