Enneagonal-great enneagrammic duoprism

The enneagonal-great enneagrammic duoprism, also known as egstedip or the 9-9/4 duoprism, is a uniform duoprism that consists of 9 enneagonal prisms and 9 great enneagrammic prisms, with 2 of each at each vertex.

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