Hyperbolic great dodecahedral honeycomb

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Great dodecahedral honeycomb
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Schläfli symbol {5,3,5}
Type regular hyperbolic honeycomb
Cells dodecahedron {5,3}
Faces pentagon {5}
Edge figure pentagon {5}
Vertex figure icosahedron {3,5}
Cells/edge {5,3}5
Cells/vertex {5,3}20
Euler characteristic 0
Dual Self-dual
Symmetry group group [5,3,5]
Properties Regular

The great dodecahedral honeycomb is one of four regular space-filling tessellations (or honeycombs) in hyperbolic 3-space.

Five dodecahedra exist on each edge, and 20 dodecahedra around each vertex.

The dihedral angle of a dodecahedron is ~116.6°, so no more than three of them can fit around an edge in Euclidean 3-space. In curved space, however, the dihedral angle depends on the size of the figure; a hyperbolic regular dodecahedron can be made with dihedral angles as small as one-sixth of a circle (if its vertices are at infinity).

There is another honeycomb in hyperbolic 3-space called the small dodecahedral honeycomb which has only 4 dodecahedra per edge. These honeycombs are also related to the 120-cell which can be considered as a honeycomb in positively-curved space (the surface of a 4 dimensional sphere), with 3 dodecahedra on each edge.

The bitruncated form, t1,2{5,3,5}, of this honeycomb has all truncated icosahedron cells.

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