Nonconvex Polyhedra - Tetrahedral Symmetry

There are two nonconvex forms, the tetrahemihexahedron and octahemioctahedron which have tetrahedral symmetry (with fundamental domain Möbius triangle (3 3 2)).

There are two Schwarz triangles that generate unique nonconvex uniform polyhedra: one right triangle (3/2 3 2), and one general triangle (3/2 3 3).

Vertex arrangement
(Convex hull)
Nonconvex forms

Tetrahedron

Rectified tetrahedron
Octahedron

(4.3/2.4.3)
3/2 3 | 2

Truncated tetrahedron

Cantellated tetrahedron
(Cuboctahedron)

(6.3/2.6.3)
3/2 3 | 3

Omnitruncated tetrahedron
(Truncated octahedron)

Snub tetrahedron
(Icosahedron)

Read more about this topic:  Nonconvex Polyhedra

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