CaRhO3 crystallizes in the monoclinic P2_1/m space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one O(1), one O(5), two equivalent O(2), two equivalent O(6), and three equivalent O(4) atoms. In the second Ca site, Ca(2) is bonded in a 9-coordinate geometry to one O(1), one O(5), two equivalent O(2), two equivalent O(7), and three equivalent O(3) atoms. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(6), two equivalent O(9), and three equivalent O(8) atoms. There are three inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(2), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the second Rh site, Rh(2) is bonded to one O(7), two equivalent O(1), and three equivalent O(9) atoms to form a mixture of edge and corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles are 49°. In the third Rh site, Rh(3) is bonded to one O(6), one O(7), two equivalent O(5), and two equivalent O(8) atoms to form a mixture of edge and corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(2), one Ca(3), and two equivalent Rh(2) atoms to form distorted OCa3Rh2 trigonal bipyramids that share corners with two equivalent O(9)Ca2Rh3 square pyramids, corners with three equivalent O(8)Ca3Rh2 square pyramids, corners with two equivalent O(1)Ca3Rh2 trigonal bipyramids, corners with three equivalent O(3)Ca3Rh2 trigonal bipyramids, edges with two equivalent O(2)Ca4Rh square pyramids, edges with three equivalent O(9)Ca2Rh3 square pyramids, edges with two equivalent O(7)Ca2Rh2 tetrahedra, and edges with two equivalent O(6)Ca4Rh trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Ca(1), two equivalent Ca(2), and one Rh(1) atom to form distorted OCa4Rh square pyramids that share corners with two equivalent O(7)Ca2Rh2 tetrahedra, corners with two equivalent O(3)Ca3Rh2 trigonal bipyramids, corners with two equivalent O(6)Ca4Rh trigonal bipyramids, edges with two equivalent O(2)Ca4Rh square pyramids,  an edgeedge with one O(7)Ca2Rh2 tetrahedra,  an edgeedge with one O(6)Ca4Rh trigonal bipyramid, edges with two equivalent O(1)Ca3Rh2 trigonal bipyramids, and edges with three equivalent O(3)Ca3Rh2 trigonal bipyramids. In the third O site, O(3) is bonded to three equivalent Ca(2) and two equivalent Rh(1) atoms to form distorted OCa3Rh2 trigonal bipyramids that share corners with two equivalent O(2)Ca4Rh square pyramids, corners with four equivalent O(7)Ca2Rh2 tetrahedra, corners with three equivalent O(1)Ca3Rh2 trigonal bipyramids, edges with three equivalent O(2)Ca4Rh square pyramids,  an edgeedge with one O(7)Ca2Rh2 tetrahedra, and edges with four equivalent O(3)Ca3Rh2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to three equivalent Ca(1) and two equivalent Rh(1) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), one Rh(1), and two equivalent Rh(3) atoms. In the sixth O site, O(6) is bonded to two equivalent Ca(1), two equivalent Ca(3), and one Rh(3) atom to form distorted OCa4Rh trigonal bipyramids that share corners with two equivalent O(9)Ca2Rh3 square pyramids, corners with two equivalent O(8)Ca3Rh2 square pyramids, corners with two equivalent O(2)Ca4Rh square pyramids,  a cornercorner with one O(7)Ca2Rh2 tetrahedra,  an edgeedge with one O(9)Ca2Rh3 square pyramid,  an edgeedge with one O(2)Ca4Rh square pyramid, edges with three equivalent O(8)Ca3Rh2 square pyramids, edges with two equivalent O(1)Ca3Rh2 trigonal bipyramids, and edges with two equivalent O(6)Ca4Rh trigonal bipyramids. In the seventh O site, O(7) is bonded to two equivalent Ca(2), one Rh(2), and one Rh(3) atom to form distorted OCa2Rh2 tetrahedra that share corners with two equivalent O(8)Ca3Rh2 square pyramids, corners with two equivalent O(2)Ca4Rh square pyramids, corners with three equivalent O(9)Ca2Rh3 square pyramids, corners with two equivalent O(7)Ca2Rh2 tetrahedra,  a cornercorner with one O(6)Ca4Rh trigonal bipyramid, corners with four equivalent O(3)Ca3Rh2 trigonal bipyramids,  an edgeedge with one O(2)Ca4Rh square pyramid,  an edgeedge with one O(3)Ca3Rh2 trigonal bipyramid, and edges with two equivalent O(1)Ca3Rh2 trigonal bipyramids. In the eighth O site, O(8) is bonded to three equivalent Ca(3) and two equivalent Rh(3) atoms to form distorted OCa3Rh2 square pyramids that share corners with four equivalent O(9)Ca2Rh3 square pyramids, corners with two equivalent O(7)Ca2Rh2 tetrahedra, corners with two equivalent O(6)Ca4Rh trigonal bipyramids, corners with three equivalent O(1)Ca3Rh2 trigonal bipyramids,  an edgeedge with one O(9)Ca2Rh3 square pyramid, edges with four equivalent O(8)Ca3Rh2 square pyramids, and edges with three equivalent O(6)Ca4Rh trigonal bipyramids. In the ninth O site, O(9) is bonded to two equivalent Ca(3) and three equivalent Rh(2) atoms to form distorted OCa2Rh3 square pyramids that share corners with four equivalent O(8)Ca3Rh2 square pyramids, corners with three equivalent O(7)Ca2Rh2 tetrahedra, corners with two equivalent O(1)Ca3Rh2 trigonal bipyramids, corners with two equivalent O(6)Ca4Rh trigonal bipyramids,  an edgeedge with one O(8)Ca3Rh2 square pyramid, edges with four equivalent O(9)Ca2Rh3 square pyramids,  an edgeedge with one O(6)Ca4Rh trigonal bipyramid, and edges with three equivalent O(1)Ca3Rh2 trigonal bipyramids.
CaRhO3 crystallizes in the monoclinic P2_1/m space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one O(1), one O(5), two equivalent O(2), two equivalent O(6), and three equivalent O(4) atoms. The Ca(1)-O(1) bond length is 2.59 Å. The Ca(1)-O(5) bond length is 2.72 Å. Both Ca(1)-O(2) bond lengths are 2.38 Å. Both Ca(1)-O(6) bond lengths are 2.42 Å. There are two shorter (2.56 Å) and one longer (2.67 Å) Ca(1)-O(4) bond length. In the second Ca site, Ca(2) is bonded in a 9-coordinate geometry to one O(1), one O(5), two equivalent O(2), two equivalent O(7), and three equivalent O(3) atoms. The Ca(2)-O(1) bond length is 2.58 Å. The Ca(2)-O(5) bond length is 2.87 Å. Both Ca(2)-O(2) bond lengths are 2.37 Å. Both Ca(2)-O(7) bond lengths are 2.39 Å. There is one shorter (2.43 Å) and two longer (2.50 Å) Ca(2)-O(3) bond lengths. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(6), two equivalent O(9), and three equivalent O(8) atoms. The Ca(3)-O(1) bond length is 2.70 Å. Both Ca(3)-O(6) bond lengths are 2.32 Å. Both Ca(3)-O(9) bond lengths are 2.45 Å. There is one shorter (2.39 Å) and two longer (2.49 Å) Ca(3)-O(8) bond lengths. There are three inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(2), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles are 52°. The Rh(1)-O(2) bond length is 1.95 Å. The Rh(1)-O(5) bond length is 1.95 Å. Both Rh(1)-O(3) bond lengths are 2.02 Å. Both Rh(1)-O(4) bond lengths are 2.00 Å. In the second Rh site, Rh(2) is bonded to one O(7), two equivalent O(1), and three equivalent O(9) atoms to form a mixture of edge and corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles are 49°. The Rh(2)-O(7) bond length is 1.92 Å. Both Rh(2)-O(1) bond lengths are 2.00 Å. There is one shorter (2.04 Å) and two longer (2.08 Å) Rh(2)-O(9) bond lengths. In the third Rh site, Rh(3) is bonded to one O(6), one O(7), two equivalent O(5), and two equivalent O(8) atoms to form a mixture of edge and corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. The Rh(3)-O(6) bond length is 2.00 Å. The Rh(3)-O(7) bond length is 2.00 Å. Both Rh(3)-O(5) bond lengths are 1.98 Å. Both Rh(3)-O(8) bond lengths are 2.03 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(2), one Ca(3), and two equivalent Rh(2) atoms to form distorted OCa3Rh2 trigonal bipyramids that share corners with two equivalent O(9)Ca2Rh3 square pyramids, corners with three equivalent O(8)Ca3Rh2 square pyramids, corners with two equivalent O(1)Ca3Rh2 trigonal bipyramids, corners with three equivalent O(3)Ca3Rh2 trigonal bipyramids, edges with two equivalent O(2)Ca4Rh square pyramids, edges with three equivalent O(9)Ca2Rh3 square pyramids, edges with two equivalent O(7)Ca2Rh2 tetrahedra, and edges with two equivalent O(6)Ca4Rh trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Ca(1), two equivalent Ca(2), and one Rh(1) atom to form distorted OCa4Rh square pyramids that share corners with two equivalent O(7)Ca2Rh2 tetrahedra, corners with two equivalent O(3)Ca3Rh2 trigonal bipyramids, corners with two equivalent O(6)Ca4Rh trigonal bipyramids, edges with two equivalent O(2)Ca4Rh square pyramids,  an edgeedge with one O(7)Ca2Rh2 tetrahedra,  an edgeedge with one O(6)Ca4Rh trigonal bipyramid, edges with two equivalent O(1)Ca3Rh2 trigonal bipyramids, and edges with three equivalent O(3)Ca3Rh2 trigonal bipyramids. In the third O site, O(3) is bonded to three equivalent Ca(2) and two equivalent Rh(1) atoms to form distorted OCa3Rh2 trigonal bipyramids that share corners with two equivalent O(2)Ca4Rh square pyramids, corners with four equivalent O(7)Ca2Rh2 tetrahedra, corners with three equivalent O(1)Ca3Rh2 trigonal bipyramids, edges with three equivalent O(2)Ca4Rh square pyramids,  an edgeedge with one O(7)Ca2Rh2 tetrahedra, and edges with four equivalent O(3)Ca3Rh2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to three equivalent Ca(1) and two equivalent Rh(1) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), one Rh(1), and two equivalent Rh(3) atoms. In the sixth O site, O(6) is bonded to two equivalent Ca(1), two equivalent Ca(3), and one Rh(3) atom to form distorted OCa4Rh trigonal bipyramids that share corners with two equivalent O(9)Ca2Rh3 square pyramids, corners with two equivalent O(8)Ca3Rh2 square pyramids, corners with two equivalent O(2)Ca4Rh square pyramids,  a cornercorner with one O(7)Ca2Rh2 tetrahedra,  an edgeedge with one O(9)Ca2Rh3 square pyramid,  an edgeedge with one O(2)Ca4Rh square pyramid, edges with three equivalent O(8)Ca3Rh2 square pyramids, edges with two equivalent O(1)Ca3Rh2 trigonal bipyramids, and edges with two equivalent O(6)Ca4Rh trigonal bipyramids. In the seventh O site, O(7) is bonded to two equivalent Ca(2), one Rh(2), and one Rh(3) atom to form distorted OCa2Rh2 tetrahedra that share corners with two equivalent O(8)Ca3Rh2 square pyramids, corners with two equivalent O(2)Ca4Rh square pyramids, corners with three equivalent O(9)Ca2Rh3 square pyramids, corners with two equivalent O(7)Ca2Rh2 tetrahedra,  a cornercorner with one O(6)Ca4Rh trigonal bipyramid, corners with four equivalent O(3)Ca3Rh2 trigonal bipyramids,  an edgeedge with one O(2)Ca4Rh square pyramid,  an edgeedge with one O(3)Ca3Rh2 trigonal bipyramid, and edges with two equivalent O(1)Ca3Rh2 trigonal bipyramids. In the eighth O site, O(8) is bonded to three equivalent Ca(3) and two equivalent Rh(3) atoms to form distorted OCa3Rh2 square pyramids that share corners with four equivalent O(9)Ca2Rh3 square pyramids, corners with two equivalent O(7)Ca2Rh2 tetrahedra, corners with two equivalent O(6)Ca4Rh trigonal bipyramids, corners with three equivalent O(1)Ca3Rh2 trigonal bipyramids,  an edgeedge with one O(9)Ca2Rh3 square pyramid, edges with four equivalent O(8)Ca3Rh2 square pyramids, and edges with three equivalent O(6)Ca4Rh trigonal bipyramids. In the ninth O site, O(9) is bonded to two equivalent Ca(3) and three equivalent Rh(2) atoms to form distorted OCa2Rh3 square pyramids that share corners with four equivalent O(8)Ca3Rh2 square pyramids, corners with three equivalent O(7)Ca2Rh2 tetrahedra, corners with two equivalent O(1)Ca3Rh2 trigonal bipyramids, corners with two equivalent O(6)Ca4Rh trigonal bipyramids,  an edgeedge with one O(8)Ca3Rh2 square pyramid, edges with four equivalent O(9)Ca2Rh3 square pyramids,  an edgeedge with one O(6)Ca4Rh trigonal bipyramid, and edges with three equivalent O(1)Ca3Rh2 trigonal bipyramids.