Ge7(H2O11)2 crystallizes in the trigonal R3m space group. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form distorted GeO6 octahedra that share corners with three equivalent Ge(3)O4 tetrahedra,  an edgeedge with one Ge(2)O6 octahedra, and edges with two equivalent Ge(1)O6 octahedra. In the second Ge site, Ge(2) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form GeO6 octahedra that share corners with three equivalent Ge(3)O4 tetrahedra and edges with three equivalent Ge(1)O6 octahedra. In the third Ge site, Ge(3) is bonded to one O(4), one O(5), and two equivalent O(3) atoms to form corner-sharing GeO4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-51°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. In the second H site, H(2) is bonded in a linear geometry to one O(2) and one O(7) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to three equivalent Ge(1) and one H(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ge(2), two equivalent Ge(1), and one H(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(3) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(3) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ge(2) and one Ge(3) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one O(7) atom. In the seventh O site, O(7) is bonded in a single-bond geometry to one H(2) and one O(6) atom.
Ge7(H2O11)2 crystallizes in the trigonal R3m space group. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form distorted GeO6 octahedra that share corners with three equivalent Ge(3)O4 tetrahedra,  an edgeedge with one Ge(2)O6 octahedra, and edges with two equivalent Ge(1)O6 octahedra. The Ge(1)-O(1) bond length is 2.17 Å. The Ge(1)-O(4) bond length is 1.79 Å. Both Ge(1)-O(2) bond lengths are 2.13 Å. Both Ge(1)-O(3) bond lengths are 1.79 Å. In the second Ge site, Ge(2) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form GeO6 octahedra that share corners with three equivalent Ge(3)O4 tetrahedra and edges with three equivalent Ge(1)O6 octahedra. All Ge(2)-O(2) bond lengths are 2.04 Å. All Ge(2)-O(5) bond lengths are 1.83 Å. In the third Ge site, Ge(3) is bonded to one O(4), one O(5), and two equivalent O(3) atoms to form corner-sharing GeO4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-51°. The Ge(3)-O(4) bond length is 1.76 Å. The Ge(3)-O(5) bond length is 1.78 Å. Both Ge(3)-O(3) bond lengths are 1.76 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. The H(1)-O(1) bond length is 0.98 Å. In the second H site, H(2) is bonded in a linear geometry to one O(2) and one O(7) atom. The H(2)-O(2) bond length is 1.08 Å. The H(2)-O(7) bond length is 1.47 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to three equivalent Ge(1) and one H(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ge(2), two equivalent Ge(1), and one H(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(3) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(3) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ge(2) and one Ge(3) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one O(7) atom. The O(6)-O(7) bond length is 2.03 Å. In the seventh O site, O(7) is bonded in a single-bond geometry to one H(2) and one O(6) atom.