Snub hexecontatetrasnub-snub disoctachoron

The snub hexecontatetrasnub-snub disoctachoron or siggissido, is a nonconvex uniform polychoron that consists of 8 icosahedra, 8 great icosahedra, 64+96 regular octahedra, and 192 tetrahedra. 1 icosahedron, 1 great icosahedron, 4+6 octahedra, and 8 tetrahedra join at each vertex.

This polychoron has the same symmetry as the demitesseract, with the icosahedra and great icosahedra acting as snub tetrahedra. It can be thought as a kind of sub-symmetrical faceting of the small stellated hecatonicosachoron.

Vertex coordinates
The vertices of a snub hexecontatetrasnub-snub disoctachoron of edge length 1, centered at the origin, are given by all even permutations of:
 * (±(1+$\sqrt{5}$)/4, ±($\sqrt{5}$–1)/4, ±1/2, 0).