Pentagrammic antiprism

The pentagrammic antiprism, or stap, is a prismatic uniform polyhedron. It consists of 10 triangles and 2 pentagrams. Each vertex joins one pentagram and three triangles. As the name suggests, it is an antiprism based on a pentagram.

Vertex coordinates
A pentagrammic retroprism of edge length 1 has vertex coordinates given by:
 * (±1/2, –$\sqrt{(15+√5)/40}$, $\sqrt{(√5–1)/2}$),
 * (±($\sqrt{5√5}$–1)/4, $\sqrt{5}$, $\sqrt{5}$),
 * (0, $\sqrt{(5–2√5)/3}$, $\sqrt{(5–2√5)/20}$).