Small disnub prismatosnub octishexacosichoron

The small disnub prismatosnub octishexacosichoron, or sedsposox, is a nonconvex uniform polychoron that consists of 600 small stellated dodecahedra and 600 great icosahedra (some of which lie in the same hyperplanes, forming 600 compounds of one of each of them), 600 icosahedra and 600 great dodecahedra (forming 600 compounds of one of each of them), 4800 cuboctahedra (forming 2400 compounds of two of them), 600 rhombidodecadodecahedra, 600 small dodecicosidodecahedra, 600 truncated icosahedra, 600 small icosicosidodecahedra, and 3600 pentagrammic prisms.

One small stellated dodecahedron and one great icosahedron (one compound), one icosahedron and one great dodecahedra (one compound), eight cuboctahedra (eight compounds), five rhombidodecadodecahedra, five small dodecicosidodecahedra, five truncated icosahedra, five small icosicosidodecahedra, and five pentagrammic prisms join at each vertex.

It can be obtained as the blend of 5 small dipentary hexacositetrishecatonicosachora and 5 small dipentary prismatohexacositetrishecatonicosachora.

Vertex coordinates
Its vertices are the same as those of its regiment colonel, the small diretrosnub disnub decahecatonicosadishexacosichoron.