Octagonal-hendecagrammic duoprism

The octagonal-hendecagrammic duoprism, also known as the 8/11-3 duoprism, is a uniform duoprism that consists of 11 octagonal prisms and 8 hendecagrammic prisms, with 2 of each at each vertex.

The name can also refer to the octagonal-small hendecagrammic duoprism, octagonal-great hendecagrammic duoprism, or octagonal-grand hendecagrammic duoprism.

Vertex coordinates
The coordinates of an octagonal-hendecagrammic duoprism, centered at the origin and with edge length 2sin(3π/11), are given by: where j = 2, 4, 6, 8, 10.
 * $$\left(±\sin\frac{3\pi}{11},\,±\left(1+\sqrt2\right)\sin\frac{3\pi}{11},\,1,\,0\right),$$
 * $$\left(±\sin\frac{3\pi}{11},\,±\left(1+\sqrt2\right)\sin\frac{3\pi}{11},\,\cos\left(\frac{j\pi}{11}\right),\,±\sin\left(\frac{j\pi}{11}\right)\right),$$
 * $$\left(±\left(1+\sqrt2\right)\sin\frac{3\pi}{11},\,±\sin\frac{3\pi}{11},\,1,\,0\right),$$
 * $$\left(±\left(1+\sqrt2\right)\sin\frac{3\pi}{11},\,±\sin\frac{3\pi}{11},\,\cos\left(\frac{j\pi}{11}\right),\,±\sin\left(\frac{j\pi}{11}\right)\right),$$

Representations
An octagonal-hendecagrammic duoprism has the following Coxeter diagrams:
 * x8o x11/3o (full symmetry)
 * x4x x11/3o (BC2×I2(11) symmetry, octagons as ditetragons)