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 and the first in an infinite family of decagonal 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+$\sqrt{(5+√5)/2}$)/2, 0, ±(1+$\sqrt{2}$)/2)
 * (0, ±(1+$\sqrt{2}$)/2, ±$\sqrt{10}$/4, ±(3+$\sqrt{5+2√5}$)/4)
 * (0, ±(1+$\sqrt{5}$)/2, ±$\sqrt{5}$/2, ±1/2)
 * (±$\sqrt{5}$/4, ±(3+$\sqrt{5}$)/4, 0, ±(1+$\sqrt{10+2√5}$)/2)
 * (±$\sqrt{5}$/4, ±(3+$\sqrt{5}$)/4, ±$\sqrt{5+2√5}$/4, ±(3+$\sqrt{10+2√5}$)/4)
 * (±$\sqrt{5}$/4, ±(3+$\sqrt{5}$)/4, ±$\sqrt{10+2√5}$/2, ±1/2)
 * (±$\sqrt{5}$/2, ±1/2, 0, ±(1+$\sqrt{10+2√5}$)/2)
 * (±$\sqrt{5}$/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)