CaCr(GeO3)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), and two equivalent O(1) atoms. Cr(1) is bonded to one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form distorted CrO6 octahedra that share corners with three equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O5 trigonal bipyramids, edges with two equivalent Cr(1)O6 octahedra, and  an edgeedge with one Ge(2)O5 trigonal bipyramid. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form GeO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-68°. In the second Ge site, Ge(2) is bonded to one O(6), two equivalent O(1), and two equivalent O(3) atoms to form GeO5 trigonal bipyramids that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Ge(2)O5 trigonal bipyramids,  an edgeedge with one Cr(1)O6 octahedra, and  an edgeedge with one Ge(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-47°. There are six inequivalent O sites. In the first O site, O(5) is bonded in a rectangular see-saw-like geometry to one Ca(1), two equivalent Cr(1), and one Ge(1) atom. In the second O site, O(6) is bonded to one Ca(1), two equivalent Cr(1), and one Ge(2) atom to form distorted OCaCr2Ge tetrahedra that share corners with two equivalent O(6)CaCr2Ge tetrahedra and corners with four equivalent O(1)Ca2Ge2 tetrahedra. In the third O site, O(1) is bonded to two equivalent Ca(1) and two equivalent Ge(2) atoms to form distorted OCa2Ge2 tetrahedra that share corners with four equivalent O(6)CaCr2Ge tetrahedra and edges with two equivalent O(1)Ca2Ge2 tetrahedra. In the fourth O site, O(2) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Ge(1) atoms. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Cr(1), and two equivalent Ge(2) atoms. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(1), and one Ge(1) atom.
CaCr(GeO3)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), and two equivalent O(1) atoms. The Ca(1)-O(2) bond length is 2.49 Å. The Ca(1)-O(3) bond length is 2.62 Å. The Ca(1)-O(4) bond length is 2.35 Å. The Ca(1)-O(5) bond length is 2.50 Å. The Ca(1)-O(6) bond length is 2.47 Å. There is one shorter (2.52 Å) and one longer (2.66 Å) Ca(1)-O(1) bond length. Cr(1) is bonded to one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form distorted CrO6 octahedra that share corners with three equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O5 trigonal bipyramids, edges with two equivalent Cr(1)O6 octahedra, and  an edgeedge with one Ge(2)O5 trigonal bipyramid. The Cr(1)-O(3) bond length is 2.47 Å. The Cr(1)-O(4) bond length is 2.05 Å. There is one shorter (2.06 Å) and one longer (2.41 Å) Cr(1)-O(5) bond length. There is one shorter (2.06 Å) and one longer (2.16 Å) Cr(1)-O(6) bond length. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form GeO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-68°. The Ge(1)-O(4) bond length is 1.73 Å. The Ge(1)-O(5) bond length is 1.75 Å. Both Ge(1)-O(2) bond lengths are 1.83 Å. In the second Ge site, Ge(2) is bonded to one O(6), two equivalent O(1), and two equivalent O(3) atoms to form GeO5 trigonal bipyramids that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Ge(2)O5 trigonal bipyramids,  an edgeedge with one Cr(1)O6 octahedra, and  an edgeedge with one Ge(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-47°. The Ge(2)-O(6) bond length is 1.79 Å. There is one shorter (1.81 Å) and one longer (1.93 Å) Ge(2)-O(1) bond length. There is one shorter (1.80 Å) and one longer (2.14 Å) Ge(2)-O(3) bond length. There are six inequivalent O sites. In the first O site, O(5) is bonded in a rectangular see-saw-like geometry to one Ca(1), two equivalent Cr(1), and one Ge(1) atom. In the second O site, O(6) is bonded to one Ca(1), two equivalent Cr(1), and one Ge(2) atom to form distorted OCaCr2Ge tetrahedra that share corners with two equivalent O(6)CaCr2Ge tetrahedra and corners with four equivalent O(1)Ca2Ge2 tetrahedra. In the third O site, O(1) is bonded to two equivalent Ca(1) and two equivalent Ge(2) atoms to form distorted OCa2Ge2 tetrahedra that share corners with four equivalent O(6)CaCr2Ge tetrahedra and edges with two equivalent O(1)Ca2Ge2 tetrahedra. In the fourth O site, O(2) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Ge(1) atoms. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Cr(1), and two equivalent Ge(2) atoms. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(1), and one Ge(1) atom.