Small stelloctagonal expandiduoprism

The small stelloctagonal expandiduoprism, or sisoxdip, is a nonconvex scaliform polychoron that consists of 64 regular tetrahedraand 16 blends of 2 small cubicuboctahedra and octagonal prism. 2 tetrahedra and 4 blends join at each vertex.

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