The compounds of ten octahedra UC<sub>15</sub> and UC<sub>16</sub> are two uniform polyhedron compounds. They are composed of a symmetric arrangement of 10 octahedra, considered as triangular antiprisms, aligned with the axes of three-fold rotational symmetry of an icosahedron. The two compounds differ in the orientation of their octahedra: each compound may be transformed into the other by rotating each octahedron by 60 degrees.
For UC15, the convex hull of this compound is a nonuniform rhombicosidodecahedron. For UC16, the convex hull would be a nonuniform truncated icosahedron.
Cartesian coordinates for the vertices of this compound are all the cyclic permutations of
where ÃÂ = (1 + )/2 is the golden ratio and s is either +1 or −1. Setting s = −1 gives UC<sub>15</sub>, while s = +1 gives UC<sub>16</sub>.