Stereohedron
In geometry and crystallography, a stereohedron is a convex polyhedron that fills space isohedrally, meaning that the symmetries of the tiling take any copy of the stereohedron to any other copy.[1]
Two-dimensional analogues to the stereohedra are called planigons. Higher dimensional polytopes can also be stereohedra, while they would more accurately be called stereotopes.
Plesiohedra
[edit]A subset of stereohedra are called plesiohedrons, defined as the Voronoi cells of a symmetric Delone set.
Parallelohedrons are plesiohedra which are space-filling by translation only. Edges here are colored as parallel vectors.
| cube | hexagonal prism | rhombic dodecahedron | elongated dodecahedron | truncated octahedron | 
Other periodic stereohedra
[edit]The catoptric tessellation contain stereohedra cells. Dihedral angles are integer divisors of 180°, and are colored by their order. The first three are the fundamental domains of , , and  symmetry, represented by Coxeter-Dynkin diagrams: ![]()
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 and ![]()
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.  is a half symmetry of , and  is a quarter symmetry.
Any space-filling stereohedra with symmetry elements can be dissected into smaller identical cells which are also stereohedra. The name modifiers below, half, quarter, and eighth represent such dissections.
| Faces | 4 | 5 | 6 | 8 | 12 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Type | Tetrahedra | Square pyramid | Triangular bipyramid | Cube | Octahedron | Rhombic dodecahedron | |||||||
| Images | 1/48 (1)  | 
1/24 (2)  | 
1/12 (4)  | 
1/12 (4)  | 
1/24 (2)  | 
1/6 (8)  | 
1/6 (8)  | 
1/12 (4)  | 
1/4 (12)  | 
1 (48)  | 
1/2 (24)  | 
1/3 (16)  | 
2 (96)  | 
| Symmetry (order)  | 
C1 1  | 
C1v 2  | 
D2d 4  | 
C1v 2  | 
C1v 2  | 
C4v 8  | 
C2v 4  | 
C2v 4  | 
C3v 6  | 
Oh 48  | 
D3d 12  | 
D4h 16  | 
Oh 48  | 
| Honeycomb | Eighth pyramidille | 
Triangular pyramidille | 
Oblate tetrahedrille | 
Half pyramidille | 
Square quarter pyramidille | 
Pyramidille | 
Half oblate octahedrille | 
Quarter oblate octahedrille | 
Quarter cubille | 
Cubille | 
Oblate cubille | 
Oblate octahedrille | 
Dodecahedrille | 
Other convex polyhedra that are stereohedra but not parallelohedra nor plesiohedra include the gyrobifastigium.
| Faces | 8 | 10 | 12 | |
|---|---|---|---|---|
| Symmetry (order)  | 
D2d (8) | D4h (16) | ||
| Images | ||||
| Cell | Gyrobifastigium | Elongated gyrobifastigium  | 
Ten of diamonds | Elongated square bipyramid  | 
References
[edit]- ^ Lekkerkerker, C. G.; Gruber, Pascale (1987). Geometry of Numbers. North-Holland. p. 166. ISBN 978-0-08-096023-4.
 
- Ivanov, A. B. (2001) [1994], "Stereohedron", Encyclopedia of Mathematics, EMS Press
 - B. N. Delone, N. N. Sandakova, Theory of stereohedra Trudy Mat. Inst. Steklov., 64 (1961) pp. 28–51 (Russian)
 - Goldberg, Michael Three Infinite Families of Tetrahedral Space-Fillers Journal of Combinatorial Theory A, 16, pp. 348–354, 1974.
 - Goldberg, Michael The space-filling pentahedra, Journal of Combinatorial Theory, Series A Volume 13, Issue 3, November 1972, Pages 437-443 [1] PDF
 - Goldberg, Michael The Space-filling Pentahedra II, Journal of Combinatorial Theory 17 (1974), 375–378. PDF
 - Goldberg, Michael On the space-filling hexahedra Geom. Dedicata, June 1977, Volume 6, Issue 1, pp 99–108 [2] PDF
 - Goldberg, Michael On the space-filling heptahedra Geometriae Dedicata, June 1978, Volume 7, Issue 2, pp 175–184 [3] PDF
 - Goldberg, Michael Convex Polyhedral Space-Fillers of More than Twelve Faces. Geom. Dedicata 8, 491-500, 1979.
 - Goldberg, Michael On the space-filling octahedra, Geometriae Dedicata, January 1981, Volume 10, Issue 1, pp 323–335 [4] PDF
 - Goldberg, Michael On the Space-filling Decahedra. Structural Topology, 1982, num. Type 10-II PDF
 - Goldberg, Michael On the space-filling enneahedra Geometriae Dedicata, June 1982, Volume 12, Issue 3, pp 297–306 [5] PDF