Great stelloctagonal expandiduoprism

The great stelloctagonal expandiduoprism, or gisoxdip, is a nonconvex scaliform polychoron that consists of 64 regular tetrahedraand 16 blends of great cubicuboctahedron and cross hatch great cubicuboctahedron. 2 tetrahedra and 4 blends of great cubicuboctahedron and cross hatch great cubicuboctahedron join at each vertex.

It is constructed as a blend of 2 great tesseractitesseractihexadecachora and 2 great hexadecadisoctachora. Its vertex figure is in turn a blend of one vertex figure of each, making the vertex figure convex. It has the same symmetry as the octagonal duoprism.