Great heptagrammic-octagonal duoprism

The great heptagrammic-octagonal duoprism, also known as gishodip or the 7/3-8 duoprism, is a uniform duoprism that consists of 8 great heptagrammic prisms and 7 octagonal prisms, with 2 of each meeting at each vertex.

Coordinates
The vertex coordinates of a great heptagrammic-octagonal duoprism, centered at the origin and with edge length 2sin(3π/7), are given by:


 * (1, 0, ±sin(3π/7)(1+$\sqrt{2+√2}$), ±sin(3π/7)),
 * (1, 0, ±sin(3π/7), ±sin(3π/7)(1+$\sqrt{2}$)),
 * (cos(2π/7), ±sin(2π/7), ±sin(3π/7)(1+$\sqrt{(2+√2)/2+1/[4sin^{2}(3π/7)]}$), ±sin(3π/7)),
 * (cos(2π/7), ±sin(2π/7), ±sin(3π/7), ±sin(3π/7)(1+$\sqrt{2}$)),
 * (cos(4π/7), ±sin(4π/7), ±sin(3π/7)(1+$\sqrt{2}$), ±sin(3π/7)),
 * (cos(4π/7), ±sin(4π/7), ±sin(3π/7), ±sin(3π/7)(1+$\sqrt{2}$)),
 * (cos(6π/7), ±sin(6π/7), ±sin(3π/7)(1+$\sqrt{2}$), ±sin(3π/7)),
 * (cos(6π/7), ±sin(6π/7), ±sin(3π/7), ±sin(3π/7)(1+$\sqrt{2}$)).