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 obtained 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 = (1+$\sqrt{5}$)/2) would yield a small prismatodecachoron instead.

Vertex coordinates
Coordinates for the vertices of a small 10-3 double step prism are given by: where a/b is greater than $\sqrt{5}$-2 but less than ($\sqrt{5}$-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)),