- Sun 09 April 2017
- Maths
- #polyhedra
I am searching for polyhedra that have four edges at every vertex. The simplest ones I have found so far are the \(n\)-antiprisms, with \(2n+2\) faces, \(2n\) vertices, and \(4n\) edges. Each convex polyhedron must satisfy the polyhedral formula:
The triangular antiprism is the octahedron, which is a Platonic solid. There are four Archimedean solids that follow this rule too:
- cuboctahedron (12 vertices)
- rhombicuboctahedron (24 vertices)
- icosidodecahedron (30 vertices)
- rhombicosidodecahedron (60 vertices)
Besides the Platonic and Archimedean solids, you also have the Johnson solids. Here is a list of relevant Johnson solids:
- \(J_{15}\): Elongated square bipyramid (10 vertices)
- \(J_{27}\): Triangular orthobicupola (12 vertices)
- \(J_{57}\): Triaugmented hexagonal prism (15 vertices)
- \(J_{28}\): Square orthobicupola (16 vertices)
- \(J_{29}\): Square gyrobicupola (16 vertices)
- \(J_{35}\): Elongated triangular orthobicupola (18 vertices)
- \(J_{36}\): Elongated triangular gyrobicupola (18 vertices)
- \(J_{92}\): Triangular hebesphenorotunda (18 vertices)
- \(J_{30}\): Pentagonal orthobicupola (20 vertices)
- \(J_{31}\): Pentagonal gyrobicupola (20 vertices)
- \(J_{37}\): Elongated square gyrobicupola (24 vertices)
- \(J_{32}\): Pentagonal orthocupolarotunda (25 vertices)
- \(J_{33}\): Pentagonal gyrocupolarotunda (25 vertices)
- \(J_{34}\): Pentagonal orthobirotunda (30 vertices)
- \(J_{38}\): Elongated pentagonal orthobicupola (30 vertices)
- \(J_{39}\): Elongated pentagonal gyrobicupola (30 vertices)
- \(J_{40}\): Elongated pentagonal orthocupolarotunda (35 vertices)
- \(J_{41}\): Elongated pentagonal gyrocupolarotunda (35 vertices)
- \(J_{42}\): Elongated pentagonal orthobirotunda (40 vertices)
- \(J_{43}\): Elongated pentagonal gyrobirotunda (40 vertices)
- \(J_{72}\): Gyrate rhombicosidodecahedron (60 vertices)
- \(J_{73}\): Parabigyrate rhombicosidodecahedron (60 vertices)
- \(J_{74}\): Metabigyrate rhombicosidodecahedron (60 vertices)
- \(J_{75}\): Trigyrate rhombicosidodecahedron (60 vertices)
The number of vertices is always a multiple of 4 or 5. According to WolframAlpha, the polyhedral graph for the polyhedra with odd number of vertices has edge chromatic number equal to 5. So \(J_{57}\), \(J_{32}\), \(J_{33}\), \(J_{40}\), and \(J_{41}\) do not work for the ABCD model.