Digonal-triangular triswirlprism

The digonal-triangular triswirlprism is a convex isogonal polychoron that consists of 6 triangular antiprisms, 9 rhombic disphenoids and 36 phyllic disphenoids of two kinds obtained as a subsymmetrical faceting of the hexagonal-enneagonal duoprism. It is the simplest nontrivial member of the duoprismatic swirlprisms.

Using the ratio method, the lowest possible ratio between the longest and shortest edges is 1:$$\frac{4}{3-2\cos\frac{\pi}{9}}-2$$ ≈ 1:1.56947.

Vertex coordinates
Coordinates for the vertices of a digonal-triangular triswirlprism, assuming that the edge length differences are minimized, are given as Cartesian products of the vertices of triangle T 1 and digon D 2 with length ratio 1:1:
 * T 1 × D 2,
 * T 3 × D 4 (T 1 rotated 40 degrees and D 2 rotated 60 degrees),
 * T 5 × D 6 (T 1 rotated 80 degrees and D 2 rotated 120 degrees).