Small ditetrahedronary hexacosihecatonicosachoron

The small ditetrahedronary hexacosihecatonicosachoron, or sidtaxhi, is a nonconvex uniform polychoron that consists of 600 regular tetrahedra and 120 small ditrigonary icosidodecahedra. 4 small ditrigonary icosidodecahedra and 4 tetrahedra join at each vertex, with a variant of the truncated tetrahedron as the vertex figure.

The vertices of a small ditrigonary hexacosihecatonicosachoron of edge length 1, centered at the origin, are given by all permutations of: together with all the even permutations of:
 * (±(1+$\sqrt{5}$)/2, ±(1+$\sqrt{2}$)/2, 0, 0),
 * (±(5+$\sqrt{10}$)/4, ±(1+$\sqrt{5}$)/4, ±(1+$\sqrt{7+3√5}$)/4, ±(1+$\sqrt{5}$)/4),
 * (±(3+$\sqrt{5}$)/4, ±(3+$\sqrt{5}$)/4, ±(3+$\sqrt{5}$)/4, ±($\sqrt{5}$–1)/4),
 * (±(2+$\sqrt{5}$)/2, ±1/2, ±1/2, ±1/2),
 * (±(2+$\sqrt{5}$)/2, ±(1+$\sqrt{5}$)/4, ±($\sqrt{5}$–1)/4, 0),
 * (±(3+$\sqrt{5}$)/4, ±(5+$\sqrt{5}$)/4, 0, ±1/2),
 * (±(3+$\sqrt{5}$)/4, ±(1+$\sqrt{5}$)/4, ±(1+$\sqrt{5}$)/2, ±1/2).