Square-octagonal duoprism

The square-octagonal duoprism or sodip, also known as the 4-8 duoprism, is a uniform duoprism that consists of 4 octagonal prisms, 8 cubes and 32 vertices.

It is a prism based on the octagonal prism. As such it is also a CRF segmentochoron, designated K-4.70 on Richard Klitzing's list.

The convex hull of two orthogonal square-octagonal duoprisms is either the small disprismatotesseractihexadecachoron or the square duotruncatoprism.

This polychoron can be alternated into a digonal-square duoantiprism, although it cannot be made uniform. The octagons can also be alternated into long rectangles to create a digonal-square prismantiprismoid, which is also nonuniform.

Vertex coordinates
The vertices of a square-octagonal duoprism of edge length 1, centered at the origin, are given by:
 * (±1/2, ±1/2, ±1/2, ±(1+$\sqrt{2+√2}$)/2),
 * (±1/2, ±1/2, ±(1+$\sqrt{2}$)/2, ±1/2).