10-3 double gyrostep prism

The 10-3 double gyrostep prism is a convex isogonal polychoron that consists of 20 tetragonal disphenoids of two kinds, 20 phyllic disphenoids, and 40 irregular tetrahedra. 4 tetragonal disphenoids, 4 phyllic disphenoids, and 8 irregular tetrahedra join at each vertex. It can be obtained as one of several polyhcora formed as the convex hull of two orthogonal 10-3 step prisms.

This polychoron cannot be optimized using the ratio method, because the solution (a/b = ($\sqrt{5}$-1)/2) would yield a small prismatodecachoron instead.

Vertex coordinates
Coordinates for the vertices of a 10-3 double gyrostep prism are given by: where a/b is greater than $$\sqrt5-2$$ but less than $$\frac{\sqrt5-1}{2}$$ and k is an integer from 0 to 9.
 * (a*sin(2πk/10), a*cos(2πk/10), b*sin(6πk/10), b*cos(6πk/10)),
 * (b*sin(2πk/10), b*cos(2πk/10), a*sin(6πk/10), a*cos(6πk/10)),