Octahemioctahedron

The octahemioctahedron, or oho, is a quasiregular polyhedron and one of 10 uniform hemipolyhedra. It consists of 8 equilateral triangles and 4 "hemi" hexagons passing through its center, with two of each joining at a vertex. Its triangular faces, as well as its hemi hexagonal faces, are parallel to those of an octahedron: hence the name.

Unlike the other quasiregular hemipolyhedra, the octahemioctahedron is orientable. This is because the triangles can be grouped into two sets of four, one of which is seen as positive-density and the other seen as negative-density. In addition, while it has cubic symmetry, its Coxeter diagram also makes it uniform under tetrahedral symmetry.

The visible portion of this solid resembles a cuboctahedron with six square pyramids carved out. In fact the triangular faces are the same ones as from the cuboctahedron, while the hexagons are those of the cuboctahedron's equatorial planes.

The octahemioctahedron is topologically a torus, and is topologically identical to a looped portion of the trihexagonal tiling.

Representations
An octahemioctahedron has the following Coxeter diagrams:


 * x3/2o3x3*a
 * ß3o3x
 * ß3/2x3x

Related polyhedra
The icosidisicosahedron is a uniform polyhedron compound composed of 5 octahemioctahedra.