Triangular-great heptagrammic duoprism

The triangular-great heptagrammic duoprism, also known as tagishdip or the 3-7/3 duoprism, is a uniform duoprism that consists of 3 great heptagrammic prisms and 7 triangular prisms, with two of each at each vertex.

Vertex coordinates
The coordinates of a triangular-great heptagrammic duoprism, centered at the origin and with edge length 2sin(3π/7), are given by:
 * (0, 2sin(3π/7)$\sqrt{2}$/3, 1, 0),
 * (0, 2sin(3π/7)$\sqrt{3}$/3, cos(2π/7), ±sin(2π/7)),
 * (0, 2sin(3π/7)$\sqrt{3}$/3, cos(4π/7), ±sin(4π/7)),
 * (0, 2sin(3π/7)$\sqrt{3}$/3, cos(6π/7), ±sin(6π/7)),
 * (±sin(3π/7), –sin(3π/7)$\sqrt{3}$/3, 1, 0),
 * (±sin(3π/7), –sin(3π/7)$\sqrt{3}$/3, cos(2π/7), ±sin(2π/7)),
 * (±sin(3π/7), –sin(3π/7)$\sqrt{3}$/3, cos(4π/7), ±sin(4π/7)),
 * (±sin(3π/7), –sin(3π/7)$\sqrt{3}$/3, cos(6π/7), ±sin(6π/7)).