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.
Two-dimensional analogues to the stereohedra are called planigons. Higher dimensional polytopes can also be stereohedra, while they would more accurately be called stereotopes.
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.
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cube | hexagonal prism | rhombic dodecahedron | elongated dodecahedron | truncated octahedron |
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: ,
and
. 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 |
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Cell | Gyrobifastigium |
Elongated gyrobifastigium |
Ten of diamonds |
Elongated square bipyramid |