Enneagonal-small hendecagrammic duoprism

The enneagonal-small hendecagrammic duoprism, also known as the 9-11/2 duoprism, is a uniform duoprism that consists of 11 enneagonal prisms and 9 small hendecagrammic prisms, with 2 of each at each vertex.

Vertex coordinates
The coordinates of a enneagonal-small hendecagrammic duoprism, centered at the origin and with edge length 4sin(π/9)sin(2π/11), are given by: where j = 2, 4, 8 and k = 2, 4, 6, 8, 10.
 * $$\left(2\sin\frac{2\pi}{11},\,0,\,2\sin\frac{\pi}9,\,0\right),$$
 * $$\left(2\sin\frac{2\pi}{11},\,0,\,2\sin\frac{\pi}9\cos\left(\frac{k\pi}{11}\right),\,±2\sin\frac{\pi}9\sin\left(\frac{k\pi}{11}\right)\right),$$
 * $$\left(2\sin\frac{2\pi}{11}\cos\left(\frac{j\pi}9\right),\,±2\sin\frac{2\pi}{11}\sin\left(\frac{j\pi}9\right),\,2\sin\frac{\pi}9,\,0\right),$$
 * $$\left(2\sin\frac{2\pi}{11}\cos\left(\frac{j\pi}9\right),\,±2\sin\frac{2\pi}{11}\sin\left(\frac{j\pi}9\right),\,2\sin\frac{\pi}9\cos\left(\frac{k\pi}{11}\right),\,±2\sin\frac{\pi}9\sin\left(\frac{k\pi}{11}\right)\right),$$
 * $$\left(-\sin\frac{2\pi}{11},\,±\sqrt3\sin\frac{2\pi}{11},\,2\sin\frac{\pi}9,\,0\right),$$
 * $$\left(-\sin\frac{2\pi}{11},\,±\sqrt3\sin\frac{2\pi}{11},\,2\sin\frac{\pi}9\cos\left(\frac{k\pi}{11}\right),\,±2\sin\frac{\pi}9\sin\left(\frac{k\pi}{11}\right)\right),$$