Great duoantiprism

The great duoantiprism or 5-5/3 duoantiprism is a nonconvex uniform polychoron that consists of 10 pentagonal antiprisms, 10 pentagrammic crossed antiprisms and 50 tetrahedra obtained through the process of alternating the 10-10/3 duoprism. It and the hexadecachoron are the only uniform duoantiprisms.

The great duoantiprism can be vertex-inscribed into a small stellated hecatonicosachoron.