Snubdis antiprism (EntityTopic, 15)
From Hi.gher. Space
The snubdis antiprism, or K4.21, or cube || icosahedron is one of the segmentochora enumerated by Richard Klitzing. It is bounded by a cube, an icosahedron, six triangular prisms, eight tetrahedra and 12 square pyramids. Its faces are six squares from the cube, 20 triangles from the icosahedron, 12 squares from the edges of the cube, 12 triangles also from the edges of the cube and 24 triangles from the edges of the icosahedron that don't correspond to faces from the cube. Its edges are 12 from the cube, 30 from the icosahedron and 24 lacing edges between them (two per icosahedron vertex, overlapping three per cube vertex).
It is also the first crown jewel CRF polychoron to be discovered, and is the only polychoron which is both a segmentotope and a crown jewel.
Coordinates
<0, ±1, ±φ, 0> <±1, ±φ, 0, 0> <±φ, 0, ±1, 0> <±1, ±1, ±1, φ>
where φ = 1+√5∕2 is the golden ratio.
