A number of attractive 18-compounds of the regular tetrahedron can be constructed.
The compound illustrated above are implemented in the Wolfram Language as PolyhedronData[{"TetrahedronEighteenCompound", 1}].
This tetrahedron 18-compound is illustrated above together with its dual and common midsphere.
The common solid and convex hull are illustrated above. The convex hull has the connectivity of the hexagon-augmented truncated octahedron.
