Octagrammic antiprismatic prism

The octagrammic antiprismatic prism or stoappip is a prismatic uniform polychoron that consists of 2 octagrammic antiprisms, 2 octagrammic prisms, and 16 triangular prisms. Each vertex joins 1 octagrammic antiprism, 1 octagrammic prism, and 3 triangular prisms. As the name suggests, it is a prism based on an octagrammic antiprism. Being a prism based on an orbiform polytope, it is also a segmentochoron.

Vertex coordinates
The vertices of an octagrammic antiprismic prism, centered at the origin and with edge length 1, are given by: where $$H=\sqrt{\frac{-2+2\sqrt2+\sqrt{20-14\sqrt2}}8}$$ is the distance between the antiprism's center and the center of one of its bases.
 * $$\left(±\frac12,\,±\frac{\sqrt2-1}2,\,H,\,±\frac12\right),$$
 * $$\left(±\frac{\sqrt2-1}2,\,±\frac12,\,H,\,±\frac12\right),$$
 * $$\left(0,\,±\sqrt{\frac{2-\sqrt2}2},\,-H,\,±\frac12\right),$$
 * $$\left(±\sqrt{\frac{2-\sqrt2}2},\,0,\,-H,\,±\frac12\right),$$
 * $$\left(±\frac{\sqrt{2-\sqrt2}}2,\,±\frac{\sqrt{2-\sqrt2}}2,\,-H,\,±\frac12\right),$$

Representations
An octagrammic antiprismatic prism has the following Coxeter diagrams:
 * x2s2s8/3s (full symmetry)
 * x2s2s16/3o
 * xx xo8/3ox&#x (octagrammic prism atop gyrated octagrammic prism)