Hexagonal-great enneagrammic duoprism

The hexagonal-great enneagrammic duoprism, also known as hagstedip or the 6-9/4 duoprism, is a uniform duoprism that consists of 9 hexagonal prisms and 6 great enneagrammic prisms, with 2 of each at each vertex.

Vertex coordinates
The coordinates of a hexagonal-great enneagrammic duoprism, centered at the origin and with edge length 2sin(4π/9), are given by: where j = 2, 4, 8.
 * $$\left(±2\sin\frac{4\pi}9,\,0,\,1,\,0\right),$$
 * $$\left(±2\sin\frac{4\pi}9,\,0,\,\cos\left(\frac{j\pi}9\right),\,±\sin\left(\frac{j\pi}9\right)\right),$$
 * $$\left(±2\sin\frac{4\pi}9,\,0,\,-\frac12,\,±\frac{\sqrt3}2\right),$$
 * $$\left(±\sin\frac{4\pi}9,\,±\sqrt3\sin\frac{4\pi}9,\,1,\,0\right),$$
 * $$\left(±\sin\frac{4\pi}9,\,±\sqrt3\sin\frac{4\pi}9,\,\cos\left(\frac{j\pi}9\right),\,±\sin\left(\frac{j\pi}9\right)\right),$$
 * $$\left(±\sin\frac{4\pi}9,\,±\sqrt3\sin\frac{4\pi}9,\,-\frac12,\,±\frac{\sqrt3}2\right),$$

Representations
A hexagonal-great enneagrammic duoprism has the following Coxeter diagrams:
 * x6o x9/4o (full symmetry)
 * x3x x9/4o (A2×I2(9) symmetry, hexagons as ditrigons)