Small retrofrustary hexacositrishecatonicosachoron

The small retrofrustary hexacositrishecatonicosachoron, or sirfixthi, is a nonconvex uniform polychoron that consists of 600 octahedra, 120 dodecadodecahedra, 120 quasirhombicosidodecahedra, and 120 small rhombicosidodecahedra. 1 octahedron, 1 dodecadodecahedron, 2 quasirhombicosidodecahedra, and 2 small rhombicosidodecahedra join at each vertex.

It is in the same regiment as the antifrustary hexacositrishecatonicosachoron.