A central truncated octahedron (an octahedron with the vertices cut off at 1/3 of the way down the sides, producing a solid with 8 regular hexagon and 6 square faces), with 14 more identical truncated octahedra packed around it, showing how this solid can pack to fill space. (Also called cubeoctahedra.) This was made in Mathematica, with the polygons perforated, then thickened in Blender. An inversion of this is also available at this store, in which all of the vertices (at vector r from the origin) are relocated to 1/r, effectively turning the solid inside-out, like a sweater. The original code for the polyhedral mapping was developed by George Hart.