CaCrO2 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(4), two equivalent O(3), and three equivalent O(1) atoms to form CaO6 octahedra that share corners with two equivalent Ca(2)O6 octahedra, corners with two equivalent Cr(1)O5 square pyramids, edges with three equivalent Ca(2)O6 octahedra, edges with four equivalent Ca(1)O6 octahedra, and edges with three equivalent Cr(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 9°. In the second Ca site, Ca(2) is bonded to one O(2), two equivalent O(4), and three equivalent O(3) atoms to form CaO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra,  a cornercorner with one Cr(1)O5 square pyramid, edges with three equivalent Ca(1)O6 octahedra, edges with four equivalent Ca(2)O6 octahedra, and edges with two equivalent Cr(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 9°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted CrO5 square pyramids that share  a cornercorner with one Ca(2)O6 octahedra, corners with two equivalent Ca(1)O6 octahedra, edges with two equivalent Ca(2)O6 octahedra, edges with three equivalent Ca(1)O6 octahedra, and edges with two equivalent Cr(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 0-12°. In the second Cr site, Cr(2) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ca(1) and two equivalent Cr(1) atoms to form OCa3Cr2 square pyramids that share corners with two equivalent O(3)Ca5Cr octahedra, corners with two equivalent O(2)CaCr4 square pyramids, corners with three equivalent O(4)Ca3Cr2 square pyramids, edges with three equivalent O(3)Ca5Cr octahedra,  an edgeedge with one O(2)CaCr4 square pyramid, and edges with four equivalent O(1)Ca3Cr2 square pyramids. The corner-sharing octahedral tilt angles are 4°. In the second O site, O(2) is bonded to one Ca(2), two equivalent Cr(1), and two equivalent Cr(2) atoms to form OCaCr4 square pyramids that share  a cornercorner with one O(3)Ca5Cr octahedra, corners with two equivalent O(1)Ca3Cr2 square pyramids, corners with four equivalent O(4)Ca3Cr2 square pyramids, edges with two equivalent O(3)Ca5Cr octahedra,  an edgeedge with one O(1)Ca3Cr2 square pyramid,  an edgeedge with one O(4)Ca3Cr2 square pyramid, and edges with two equivalent O(2)CaCr4 square pyramids. The corner-sharing octahedral tilt angles are 5°. In the third O site, O(3) is bonded to two equivalent Ca(1), three equivalent Ca(2), and one Cr(1) atom to form distorted OCa5Cr octahedra that share  a cornercorner with one O(2)CaCr4 square pyramid, corners with two equivalent O(1)Ca3Cr2 square pyramids, corners with two equivalent O(4)Ca3Cr2 square pyramids, edges with four equivalent O(3)Ca5Cr octahedra, edges with two equivalent O(2)CaCr4 square pyramids, edges with three equivalent O(1)Ca3Cr2 square pyramids, and edges with three equivalent O(4)Ca3Cr2 square pyramids. In the fourth O site, O(4) is bonded to one Ca(1), two equivalent Ca(2), and two equivalent Cr(2) atoms to form OCa3Cr2 square pyramids that share corners with two equivalent O(3)Ca5Cr octahedra, corners with three equivalent O(1)Ca3Cr2 square pyramids, corners with four equivalent O(2)CaCr4 square pyramids, edges with three equivalent O(3)Ca5Cr octahedra,  an edgeedge with one O(2)CaCr4 square pyramid, and edges with two equivalent O(4)Ca3Cr2 square pyramids. The corner-sharing octahedral tilt angles are 9°.
CaCrO2 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(4), two equivalent O(3), and three equivalent O(1) atoms to form CaO6 octahedra that share corners with two equivalent Ca(2)O6 octahedra, corners with two equivalent Cr(1)O5 square pyramids, edges with three equivalent Ca(2)O6 octahedra, edges with four equivalent Ca(1)O6 octahedra, and edges with three equivalent Cr(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 9°. The Ca(1)-O(4) bond length is 2.40 Å. Both Ca(1)-O(3) bond lengths are 2.30 Å. There are two shorter (2.37 Å) and one longer (2.44 Å) Ca(1)-O(1) bond length. In the second Ca site, Ca(2) is bonded to one O(2), two equivalent O(4), and three equivalent O(3) atoms to form CaO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra,  a cornercorner with one Cr(1)O5 square pyramid, edges with three equivalent Ca(1)O6 octahedra, edges with four equivalent Ca(2)O6 octahedra, and edges with two equivalent Cr(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 9°. The Ca(2)-O(2) bond length is 2.44 Å. Both Ca(2)-O(4) bond lengths are 2.40 Å. There are two shorter (2.31 Å) and one longer (2.40 Å) Ca(2)-O(3) bond length. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted CrO5 square pyramids that share  a cornercorner with one Ca(2)O6 octahedra, corners with two equivalent Ca(1)O6 octahedra, edges with two equivalent Ca(2)O6 octahedra, edges with three equivalent Ca(1)O6 octahedra, and edges with two equivalent Cr(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 0-12°. The Cr(1)-O(3) bond length is 2.66 Å. Both Cr(1)-O(1) bond lengths are 2.08 Å. Both Cr(1)-O(2) bond lengths are 2.16 Å. In the second Cr site, Cr(2) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(4) atoms. Both Cr(2)-O(2) bond lengths are 2.15 Å. Both Cr(2)-O(4) bond lengths are 2.07 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ca(1) and two equivalent Cr(1) atoms to form OCa3Cr2 square pyramids that share corners with two equivalent O(3)Ca5Cr octahedra, corners with two equivalent O(2)CaCr4 square pyramids, corners with three equivalent O(4)Ca3Cr2 square pyramids, edges with three equivalent O(3)Ca5Cr octahedra,  an edgeedge with one O(2)CaCr4 square pyramid, and edges with four equivalent O(1)Ca3Cr2 square pyramids. The corner-sharing octahedral tilt angles are 4°. In the second O site, O(2) is bonded to one Ca(2), two equivalent Cr(1), and two equivalent Cr(2) atoms to form OCaCr4 square pyramids that share  a cornercorner with one O(3)Ca5Cr octahedra, corners with two equivalent O(1)Ca3Cr2 square pyramids, corners with four equivalent O(4)Ca3Cr2 square pyramids, edges with two equivalent O(3)Ca5Cr octahedra,  an edgeedge with one O(1)Ca3Cr2 square pyramid,  an edgeedge with one O(4)Ca3Cr2 square pyramid, and edges with two equivalent O(2)CaCr4 square pyramids. The corner-sharing octahedral tilt angles are 5°. In the third O site, O(3) is bonded to two equivalent Ca(1), three equivalent Ca(2), and one Cr(1) atom to form distorted OCa5Cr octahedra that share  a cornercorner with one O(2)CaCr4 square pyramid, corners with two equivalent O(1)Ca3Cr2 square pyramids, corners with two equivalent O(4)Ca3Cr2 square pyramids, edges with four equivalent O(3)Ca5Cr octahedra, edges with two equivalent O(2)CaCr4 square pyramids, edges with three equivalent O(1)Ca3Cr2 square pyramids, and edges with three equivalent O(4)Ca3Cr2 square pyramids. In the fourth O site, O(4) is bonded to one Ca(1), two equivalent Ca(2), and two equivalent Cr(2) atoms to form OCa3Cr2 square pyramids that share corners with two equivalent O(3)Ca5Cr octahedra, corners with three equivalent O(1)Ca3Cr2 square pyramids, corners with four equivalent O(2)CaCr4 square pyramids, edges with three equivalent O(3)Ca5Cr octahedra,  an edgeedge with one O(2)CaCr4 square pyramid, and edges with two equivalent O(4)Ca3Cr2 square pyramids. The corner-sharing octahedral tilt angles are 9°.