Ca5(GeO5)2 is beta indium sulfide-derived structured and crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form CaO6 octahedra that share corners with four equivalent Ca(2)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra, edges with two equivalent Ca(2)O6 octahedra, edges with two equivalent Ca(3)O6 octahedra, and edges with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 63-64°. In the second Ca site, Ca(2) is bonded to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms to form CaO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Ca(2)O6 octahedra, corners with four equivalent Ca(3)O6 octahedra, corners with three equivalent Ge(1)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(3)O6 octahedra, and  an edgeedge with one Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-64°. In the third Ca site, Ca(3) is bonded to one O(1), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form CaO6 octahedra that share corners with two equivalent Ca(3)O6 octahedra, corners with four equivalent Ca(2)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(2)O6 octahedra,  an edgeedge with one Ca(3)O6 octahedra, and  an edgeedge with one Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-66°. Ge(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form GeO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra, corners with two equivalent Ca(3)O6 octahedra, corners with three equivalent Ca(2)O6 octahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(2)O6 octahedra, and  an edgeedge with one Ca(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-61°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Ca(2), one Ca(3), and one Ge(1) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ca(1), two equivalent Ca(2), and one Ge(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ca(2), two equivalent Ca(3), and one Ge(1) atom. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), one Ca(3), and one Ge(1) atom to form distorted corner-sharing OCa3Ge tetrahedra. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(2) and two equivalent Ca(3) atoms.
Ca5(GeO5)2 is beta indium sulfide-derived structured and crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form CaO6 octahedra that share corners with four equivalent Ca(2)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra, edges with two equivalent Ca(2)O6 octahedra, edges with two equivalent Ca(3)O6 octahedra, and edges with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 63-64°. Both Ca(1)-O(1) bond lengths are 2.37 Å. Both Ca(1)-O(2) bond lengths are 2.41 Å. Both Ca(1)-O(4) bond lengths are 2.40 Å. In the second Ca site, Ca(2) is bonded to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms to form CaO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Ca(2)O6 octahedra, corners with four equivalent Ca(3)O6 octahedra, corners with three equivalent Ge(1)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(3)O6 octahedra, and  an edgeedge with one Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-64°. The Ca(2)-O(1) bond length is 2.33 Å. The Ca(2)-O(3) bond length is 2.50 Å. The Ca(2)-O(4) bond length is 2.49 Å. The Ca(2)-O(5) bond length is 2.35 Å. There is one shorter (2.34 Å) and one longer (2.46 Å) Ca(2)-O(2) bond length. In the third Ca site, Ca(3) is bonded to one O(1), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form CaO6 octahedra that share corners with two equivalent Ca(3)O6 octahedra, corners with four equivalent Ca(2)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(2)O6 octahedra,  an edgeedge with one Ca(3)O6 octahedra, and  an edgeedge with one Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-66°. The Ca(3)-O(1) bond length is 2.47 Å. The Ca(3)-O(4) bond length is 2.43 Å. There is one shorter (2.30 Å) and one longer (2.42 Å) Ca(3)-O(3) bond length. Both Ca(3)-O(5) bond lengths are 2.36 Å. Ge(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form GeO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra, corners with two equivalent Ca(3)O6 octahedra, corners with three equivalent Ca(2)O6 octahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(2)O6 octahedra, and  an edgeedge with one Ca(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-61°. The Ge(1)-O(1) bond length is 1.80 Å. The Ge(1)-O(2) bond length is 1.80 Å. The Ge(1)-O(3) bond length is 1.80 Å. The Ge(1)-O(4) bond length is 1.76 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Ca(2), one Ca(3), and one Ge(1) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ca(1), two equivalent Ca(2), and one Ge(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ca(2), two equivalent Ca(3), and one Ge(1) atom. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), one Ca(3), and one Ge(1) atom to form distorted corner-sharing OCa3Ge tetrahedra. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(2) and two equivalent Ca(3) atoms.