Decagonal duoprism

The decagonal duoprism or dadip, also known as the decagonal-decagonal duoprism, the 10 duoprism or the 10-10 duoprism, is a noble uniform duoprism that consists of 20 decagonal prisms, with four at each vertex. It is also the 20-9 gyrochoron. Together with its dual, it is the fourth in an infinite family of square dihedral swirlchora.

This polychoron can be alternated into a pentagonal duoantiprism, although it cannot be made uniform.

Vertex coordinates
The vertices of a decagonal duoprism of edge length 1, centered at the origin, are given by:
 * (0, ±(1+$\sqrt{5}$)/2, 0, ±(1+$\sqrt{5}$)/2)
 * (0, ±(1+$\sqrt{5}$)/2, ±$\sqrt{10+2√5}$/4, ±(3+$\sqrt{5}$)/4)
 * (0, ±(1+$\sqrt{5}$)/2, ±$\sqrt{5+2√5}$/2, ±1/2)
 * (±$\sqrt{10+2√5}$/4, ±(3+$\sqrt{5}$)/4, 0, ±(1+$\sqrt{5}$)/2)
 * (±$\sqrt{10+2√5}$/4, ±(3+$\sqrt{5}$)/4, ±$\sqrt{10+2√5}$/4, ±(3+$\sqrt{5}$)/4)
 * (±$\sqrt{10+2√5}$/4, ±(3+$\sqrt{5}$)/4, ±$\sqrt{5+2√5}$/2, ±1/2)
 * (±$\sqrt{5+2√5}$/2, ±1/2, 0, ±(1+$\sqrt{5}$)/2)
 * (±$\sqrt{5+2√5}$/2, ±1/2, ±$\sqrt{10+2√5}$/4, ±(3+$\sqrt{5}$)/4)
 * (±$\sqrt{5+2√5}$/2, ±1/2, ±$\sqrt{5+2√5}$/2, ±1/2)