Rh2O3 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles range from 12-61°. In the second Rh site, Rh(2) is bonded to one O(3), two equivalent O(2), and three equivalent O(1) atoms to form a mixture of edge and corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles range from 12-61°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Rh(1) and three equivalent Rh(2) atoms to form distorted ORh4 tetrahedra that share corners with seven equivalent O(2)Rh5 square pyramids, corners with two equivalent O(1)Rh4 tetrahedra,  an edgeedge with one O(2)Rh5 square pyramid, and edges with two equivalent O(1)Rh4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Rh(2) and three equivalent Rh(1) atoms to form ORh5 square pyramids that share corners with seven equivalent O(1)Rh4 tetrahedra, edges with four equivalent O(2)Rh5 square pyramids, and  an edgeedge with one O(1)Rh4 tetrahedra. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Rh(2) and two equivalent Rh(1) atoms.
Rh2O3 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles range from 12-61°. The Rh(1)-O(1) bond length is 2.07 Å. Both Rh(1)-O(3) bond lengths are 1.98 Å. There is one shorter (2.11 Å) and two longer (2.24 Å) Rh(1)-O(2) bond lengths. In the second Rh site, Rh(2) is bonded to one O(3), two equivalent O(2), and three equivalent O(1) atoms to form a mixture of edge and corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles range from 12-61°. The Rh(2)-O(3) bond length is 1.99 Å. Both Rh(2)-O(2) bond lengths are 2.20 Å. There are two shorter (2.03 Å) and one longer (2.15 Å) Rh(2)-O(1) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Rh(1) and three equivalent Rh(2) atoms to form distorted ORh4 tetrahedra that share corners with seven equivalent O(2)Rh5 square pyramids, corners with two equivalent O(1)Rh4 tetrahedra,  an edgeedge with one O(2)Rh5 square pyramid, and edges with two equivalent O(1)Rh4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Rh(2) and three equivalent Rh(1) atoms to form ORh5 square pyramids that share corners with seven equivalent O(1)Rh4 tetrahedra, edges with four equivalent O(2)Rh5 square pyramids, and  an edgeedge with one O(1)Rh4 tetrahedra. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Rh(2) and two equivalent Rh(1) atoms.