Small snubspinosnub prismatosnub heptishexacosichoron

The small snubspinosnub prismatosnub heptishexacosichoron, or sosenspeshex, is a nonconvex uniform polychoron that consists of 600 great icosahedra and 600 small stellated dodecahedra (some of which lie in the same hyperplanes, forming 600 compounds of one of each), 1200 great dodecahedra (forming 600 pentagonal retrosnub pseudodisoctahedra), 2400 cuboctahedra and 2400 cubohemioctahedra (forming 2400 compounds of one of each), 600 octahemioctahedra (forming 120 icosidisicosahedra), 600 small ditrigonal dodecicosidodecahedra, 600 rhombidodecadodecahedra, 600 truncated icosahedra, and 3600 pentagrammic prisms.

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

It can be obtained as the blend of 5 small dipentary dishecatonicosihexacosidishecatonicosachora and 5 small capped dipentary prismatohexacositrishecatonicosachora. In the process, some of the cuboctahedron and cubohemioctahedron cells blend out.

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