Cd2Ge7O16 crystallizes in the tetragonal P-4b2 space group. Cd(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form GeO4 tetrahedra that share corners with two equivalent Ge(2)O6 octahedra and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-62°. In the second Ge site, Ge(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing GeO6 octahedra. In the third Ge site, Ge(3) is bonded to four equivalent O(4) atoms to form corner-sharing GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 62°. There are four inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Cd(1), one Ge(1), and one Ge(2) atom. In the second O site, O(4) is bonded in a distorted trigonal planar geometry to one Cd(1), one Ge(2), and one Ge(3) atom. In the third O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent Ge(1) atoms. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to one Cd(1), one Ge(1), and one Ge(2) atom.
Cd2Ge7O16 crystallizes in the tetragonal P-4b2 space group. Cd(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Both Cd(1)-O(2) bond lengths are 2.27 Å. Both Cd(1)-O(3) bond lengths are 2.51 Å. Both Cd(1)-O(4) bond lengths are 2.26 Å. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form GeO4 tetrahedra that share corners with two equivalent Ge(2)O6 octahedra and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-62°. The Ge(1)-O(2) bond length is 1.77 Å. The Ge(1)-O(3) bond length is 1.76 Å. There is one shorter (1.76 Å) and one longer (1.78 Å) Ge(1)-O(1) bond length. In the second Ge site, Ge(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing GeO6 octahedra. Both Ge(2)-O(2) bond lengths are 1.89 Å. Both Ge(2)-O(3) bond lengths are 1.86 Å. Both Ge(2)-O(4) bond lengths are 1.93 Å. In the third Ge site, Ge(3) is bonded to four equivalent O(4) atoms to form corner-sharing GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 62°. All Ge(3)-O(4) bond lengths are 1.77 Å. There are four inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Cd(1), one Ge(1), and one Ge(2) atom. In the second O site, O(4) is bonded in a distorted trigonal planar geometry to one Cd(1), one Ge(2), and one Ge(3) atom. In the third O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent Ge(1) atoms. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to one Cd(1), one Ge(1), and one Ge(2) atom.