Grand hecatonicosachoron

The grand hecatonicosachoron, or gahi, also commonly called the grand 120-cell, is one of the 10 regular Schläfli–Hess polychora. It has 120 dodecahedra as cells, joining 5 to an edge and 20 to a vertex in the form of a great icosahedron.

It is a faceting of the hexacosichoron, sharing its vertices and edges, and sharing the faces of the great hecatonicosachoron.

Vertex coordinates
Its vertices are the same as those of its regiment colonel, the hexacosichoron.