Ba2CdGe2O7 crystallizes in the tetragonal P-42_1m space group. Ba(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(2), and four equivalent O(3) atoms. Cd(1) is bonded to four equivalent O(3) atoms to form CdO4 tetrahedra that share corners with four equivalent Ge(1)O4 tetrahedra. Ge(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form GeO4 tetrahedra that share  a cornercorner with one Ge(1)O4 tetrahedra and corners with two equivalent Cd(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1) and two equivalent Ge(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Ba(1) and one Ge(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Cd(1), and one Ge(1) atom.
Ba2CdGe2O7 crystallizes in the tetragonal P-42_1m space group. Ba(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(2), and four equivalent O(3) atoms. The Ba(1)-O(1) bond length is 2.78 Å. There is one shorter (2.77 Å) and two longer (2.96 Å) Ba(1)-O(2) bond lengths. There are two shorter (2.76 Å) and two longer (2.93 Å) Ba(1)-O(3) bond lengths. Cd(1) is bonded to four equivalent O(3) atoms to form CdO4 tetrahedra that share corners with four equivalent Ge(1)O4 tetrahedra. All Cd(1)-O(3) bond lengths are 2.17 Å. Ge(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form GeO4 tetrahedra that share  a cornercorner with one Ge(1)O4 tetrahedra and corners with two equivalent Cd(1)O4 tetrahedra. The Ge(1)-O(1) bond length is 1.80 Å. The Ge(1)-O(2) bond length is 1.73 Å. Both Ge(1)-O(3) bond lengths are 1.76 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1) and two equivalent Ge(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Ba(1) and one Ge(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Cd(1), and one Ge(1) atom.