CaCr2(CuO4)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to one O(1), one O(4), one O(7), one O(8), and two equivalent O(3) atoms to form CaO6 octahedra that share corners with three equivalent Cr(1)O4 tetrahedra, corners with three equivalent Cr(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra, and edges with two equivalent Cu(1)O5 trigonal bipyramids. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form CrO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 36-60°. In the second Cr site, Cr(2) is bonded to one O(3), one O(5), one O(6), and one O(8) atom to form CrO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra and corners with three equivalent Cu(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 49-64°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(1), one O(3), one O(5), one O(6), and one O(7) atom to form distorted CuO5 trigonal bipyramids that share corners with two equivalent Cr(1)O4 tetrahedra, corners with three equivalent Cr(2)O4 tetrahedra, and edges with two equivalent Ca(1)O6 octahedra. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), one O(6), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one Cu(1) atom. In the second O site, O(8) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(2), and one Cu(2) atom. In the third O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(1), and one Cu(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to one Cr(1) and one Cu(2) atom. In the fifth O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(1), one Cr(2), and one Cu(1) atom. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one Cu(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Cr(2) and one Cu(1) atom. In the eighth O site, O(6) is bonded in a distorted trigonal planar geometry to one Cr(2), one Cu(1), and one Cu(2) atom.
CaCr2(CuO4)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to one O(1), one O(4), one O(7), one O(8), and two equivalent O(3) atoms to form CaO6 octahedra that share corners with three equivalent Cr(1)O4 tetrahedra, corners with three equivalent Cr(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra, and edges with two equivalent Cu(1)O5 trigonal bipyramids. The Ca(1)-O(1) bond length is 2.36 Å. The Ca(1)-O(4) bond length is 2.32 Å. The Ca(1)-O(7) bond length is 2.40 Å. The Ca(1)-O(8) bond length is 2.29 Å. There is one shorter (2.31 Å) and one longer (2.42 Å) Ca(1)-O(3) bond length. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form CrO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 36-60°. The Cr(1)-O(1) bond length is 1.71 Å. The Cr(1)-O(2) bond length is 1.68 Å. The Cr(1)-O(4) bond length is 1.71 Å. The Cr(1)-O(7) bond length is 1.69 Å. In the second Cr site, Cr(2) is bonded to one O(3), one O(5), one O(6), and one O(8) atom to form CrO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra and corners with three equivalent Cu(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 49-64°. The Cr(2)-O(3) bond length is 1.72 Å. The Cr(2)-O(5) bond length is 1.67 Å. The Cr(2)-O(6) bond length is 1.70 Å. The Cr(2)-O(8) bond length is 1.70 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(1), one O(3), one O(5), one O(6), and one O(7) atom to form distorted CuO5 trigonal bipyramids that share corners with two equivalent Cr(1)O4 tetrahedra, corners with three equivalent Cr(2)O4 tetrahedra, and edges with two equivalent Ca(1)O6 octahedra. The Cu(1)-O(1) bond length is 1.97 Å. The Cu(1)-O(3) bond length is 2.44 Å. The Cu(1)-O(5) bond length is 1.94 Å. The Cu(1)-O(6) bond length is 2.11 Å. The Cu(1)-O(7) bond length is 2.10 Å. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), one O(6), and one O(8) atom. The Cu(2)-O(2) bond length is 1.98 Å. The Cu(2)-O(4) bond length is 2.06 Å. The Cu(2)-O(6) bond length is 2.05 Å. The Cu(2)-O(8) bond length is 2.02 Å. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one Cu(1) atom. In the second O site, O(8) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(2), and one Cu(2) atom. In the third O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(1), and one Cu(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to one Cr(1) and one Cu(2) atom. In the fifth O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(1), one Cr(2), and one Cu(1) atom. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one Cu(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Cr(2) and one Cu(1) atom. In the eighth O site, O(6) is bonded in a distorted trigonal planar geometry to one Cr(2), one Cu(1), and one Cu(2) atom.