Small retrohexacosidishecatonicosachoron

The small retrohexacosidishecatonicosachoron, or sirxady, is a nonconvex uniform polychoron that consists of 600 truncated tetrahedra, 120 truncated dodecahedra, and 120 great rhombicosidodecahedra. Two truncated tetrahedra, two truncated dodecahedra, and four great rhombicosidodecahedra join at each vertex.

Vertex coordinates
The vertices are the same as those of the regiment colonel, the sphenoverted hecatonicosidishexacosichoron.