Small snubretrosnub snub pentishexacosipentishecatonicosachoron

The small snubretrosnub snub pentishexacosipentishecatonicosachoron, or sosirsaspoxphi, is a nonconvex uniform polychoron that consists of 600 great icosahedra, 600 icosahedra and 600 great dodecahedra (some of which lie in the same hyperplanes, forming 600 compounds of one of each), 2400 octahemioctahedra and 2400 cuboctahedra (forming 2400 compounds of one of each), 600 cubohemioctahedra (forming 120 great antirhombicosahedra), 600 rhombidodecadodecahedra, 600 small ditrigonal dodecicosidodecahedra, and 3000 truncated tetrahedra (600 of which form 120 truncated chiricosahedra).

One great icosahedron, one icosahedron and one great dodecahedron (two compounds), four octahemioctahedra and four cuboctahedra (eight compounds), one cubohemioctahedron (one compound), five rhombidodecadodecahedra, five small ditrigonal dodecicosidodecahedra, and five truncated tetrahedra (one compound, four single) join at each vertex.

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

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