Heptagrammic-octagonal duoprism

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

The name can also refer to the great heptagrammic-octagonal duoprism.

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


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