Small retroditetrahedronary hexacosidishecatonicosachoron

The small retroditetrahedronary hexacosidishecatonicosachoron, or sirdtaxady, is a nonconvex uniform polychoron that consists of 600 regular tetrahedra, 120 regular dodecahedra, and 120 icosidodecahedra. 4 dodecahedra, 4 tetrahedra, and 6 icosidodecahedra join at each vertex.

It is in the same regiment as the small ditetrahedronary hexacosihecatoniosachoron.