CaSn(GeO3)2 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Sn(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. Ge(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form corner-sharing GeO4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Ca(1) and two equivalent Ge(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Sn(1), and one Ge(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Sn(1), and one Ge(1) atom.
CaSn(GeO3)2 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Both Ca(1)-O(2) bond lengths are 2.29 Å. Both Ca(1)-O(3) bond lengths are 2.40 Å. There are two shorter (2.78 Å) and two longer (2.94 Å) Ca(1)-O(1) bond lengths. Sn(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. Both Sn(1)-O(2) bond lengths are 2.18 Å. Both Sn(1)-O(3) bond lengths are 2.43 Å. Ge(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form corner-sharing GeO4 tetrahedra. The Ge(1)-O(2) bond length is 1.75 Å. The Ge(1)-O(3) bond length is 1.73 Å. There is one shorter (1.83 Å) and one longer (1.86 Å) Ge(1)-O(1) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Ca(1) and two equivalent Ge(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Sn(1), and one Ge(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Sn(1), and one Ge(1) atom.