Heptagonal duoprism

The heptagonal duoprism or hedip, also known as the heptagonal-heptagonal duoprism, the 7 duoprism or the 7-7 duoprism, is a noble uniform duoprism that consists of 14 heptagonal prisms and 49 vertices. It is also the 14-6 gyrochoron. Together with its dual, it is the first in an infinite family of heptagonal dihedral swirlchora.

Vertex coordinates
The coordinates of a heptagonal duoprism, centered at the origin and with edge length 2sin(π/7), are given by:
 * (1, 0, 1, 0),
 * (1, 0, cos(2π/7), ±sin(2π/7)),
 * (1, 0, cos(4π/7), ±sin(4π/7)),
 * (1, 0, cos(6π/7), ±sin(6π/7)),
 * (cos(2π/7), ±sin(2π/7), 1, 0),
 * (cos(2π/7), ±sin(2π/7), cos(2π/7), ±sin(2π/7)),
 * (cos(2π/7), ±sin(2π/7), cos(4π/7), ±sin(4π/7)),
 * (cos(2π/7), ±sin(2π/7), cos(6π/7), ±sin(6π/7)),
 * (cos(4π/7), ±sin(4π/7), 1, 0),
 * (cos(4π/7), ±sin(4π/7), cos(2π/7), ±sin(2π/7)),
 * (cos(4π/7), ±sin(4π/7), cos(4π/7), ±sin(4π/7)),
 * (cos(4π/7), ±sin(4π/7), cos(6π/7), ±sin(6π/7)),
 * (cos(6π/7), ±sin(6π/7), 1, 0),
 * (cos(6π/7), ±sin(6π/7), cos(2π/7), ±sin(2π/7)),
 * (cos(6π/7), ±sin(6π/7), cos(4π/7), ±sin(4π/7)),
 * (cos(6π/7), ±sin(6π/7), cos(6π/7), ±sin(6π/7)).