Compound of twelve pentagrammic crossed antiprisms with rotational freedom

This uniform polyhedron compound is a symmetric arrangement of 12 pentagrammic crossed antiprisms. It can be constructed by inscribing one pair of pentagrammic crossed antiprisms within a great icosahedron, in each of the six possible ways, and then rotating each by an equal and opposite angle θ.

Compound of twelve pentagrammic crossed antiprisms with rotational freedom
TypeUniform compound
IndexUC28
Polyhedra12 pentagrammic crossed antiprisms
Faces120 triangles, 24 pentagrams
Edges240
Vertices120
Symmetry groupicosahedral (Ih)
Subgroup restricting to one constituent10-fold improper rotation (S10)

When θ is 36 degrees, the antiprisms coincide in pairs to yield (two superimposed copies of) the compound of six pentagrammic crossed antiprisms (without rotational freedom).

This compound shares its vertices with the compound of twelve pentagonal antiprisms with rotational freedom.

References

  • Skilling, John (1976), "Uniform Compounds of Uniform Polyhedra", Mathematical Proceedings of the Cambridge Philosophical Society, 79: 447–457, doi:10.1017/S0305004100052440, MR 0397554.


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