# Bidiakis cube

Bidiakis cube
The Bidiakis cube
Vertices12
Edges18
Diameter3
Girth4
Automorphisms8 (D4)
Chromatic number3
Chromatic index3
PropertiesCubic
Hamiltonian
Triangle-free
Polyhedral
Planar
Table of graphs and parameters

In the mathematical field of graph theory, the Bidiakis cube is a 3-regular graph with 12 vertices and 18 edges.[1]

## Construction

The Bidiakis cube is a cubic Hamiltonian graph and can be defined by the LCF notation [-6,4,-4]4.

The Bidiakis cube can also be constructed from a cube by adding edges across the top and bottom faces which connect the centres of opposite sides of the faces. The two additional edges need to be perpendicular to each other. With this construction, the Bidiakis cube is a polyhedral graph, and can be realized as a convex polyhedron. Therefore, by Steinitz's theorem, it is a 3-vertex-connected simple planar graph.[2][3]

## Algebraic properties

The Bidiakis cube is not a vertex-transitive graph and its full automorphism group is isomorphic to the dihedral group of order 8, the group of symmetries of a square, including both rotations and reflections.

The characteristic polynomial of the Bidiakis cube is ${\displaystyle (x-3)(x-2)(x^{4})(x+1)(x+2)(x^{2}+x-4)^{2}}$.

## References

1. ^ Weisstein, Eric W. "Bidiakis cube". MathWorld.
2. ^ Branko Grünbaum, Convex Polytopes, 2nd edition, prepared by Volker Kaibel, Victor Klee, and Günter M. Ziegler, 2003, ISBN 0-387-40409-0, ISBN 978-0-387-40409-7, 466pp.
3. ^