Ge7N2O15 crystallizes in the monoclinic C2/c space group. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form GeO4 tetrahedra that share  a cornercorner with one Ge(4)N2O4 octahedra,  a cornercorner with one Ge(2)O4 tetrahedra, and corners with two equivalent Ge(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. In the second Ge site, Ge(2) is bonded to one O(1), one O(3), one O(6), and one O(8) atom to form corner-sharing GeO4 tetrahedra. In the third Ge site, Ge(3) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form GeO4 tetrahedra that share  a cornercorner with one Ge(4)N2O4 octahedra,  a cornercorner with one Ge(2)O4 tetrahedra, and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. In the fourth Ge site, Ge(4) is bonded to two equivalent N(1), two equivalent O(5), and two equivalent O(7) atoms to form corner-sharing GeN2O4 octahedra. N(1) is bonded in a bent 120 degrees geometry to one Ge(4) and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ge(2) and one Ge(3) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ge(1) and one Ge(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to two equivalent Ge(2) atoms. 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(3) and one Ge(4) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Ge(1) and one Ge(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(4) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Ge(2) and one N(1) atom.
Ge7N2O15 crystallizes in the monoclinic C2/c space group. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form GeO4 tetrahedra that share  a cornercorner with one Ge(4)N2O4 octahedra,  a cornercorner with one Ge(2)O4 tetrahedra, and corners with two equivalent Ge(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. The Ge(1)-O(2) bond length is 1.77 Å. The Ge(1)-O(4) bond length is 1.75 Å. The Ge(1)-O(6) bond length is 1.78 Å. The Ge(1)-O(7) bond length is 1.75 Å. In the second Ge site, Ge(2) is bonded to one O(1), one O(3), one O(6), and one O(8) atom to form corner-sharing GeO4 tetrahedra. The Ge(2)-O(1) bond length is 1.73 Å. The Ge(2)-O(3) bond length is 1.78 Å. The Ge(2)-O(6) bond length is 1.72 Å. The Ge(2)-O(8) bond length is 1.92 Å. In the third Ge site, Ge(3) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form GeO4 tetrahedra that share  a cornercorner with one Ge(4)N2O4 octahedra,  a cornercorner with one Ge(2)O4 tetrahedra, and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. The Ge(3)-O(1) bond length is 1.78 Å. The Ge(3)-O(2) bond length is 1.76 Å. The Ge(3)-O(4) bond length is 1.76 Å. The Ge(3)-O(5) bond length is 1.75 Å. In the fourth Ge site, Ge(4) is bonded to two equivalent N(1), two equivalent O(5), and two equivalent O(7) atoms to form corner-sharing GeN2O4 octahedra. Both Ge(4)-N(1) bond lengths are 2.29 Å. Both Ge(4)-O(5) bond lengths are 1.85 Å. Both Ge(4)-O(7) bond lengths are 1.84 Å. N(1) is bonded in a bent 120 degrees geometry to one Ge(4) and one O(8) atom. The N(1)-O(8) bond length is 1.28 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ge(2) and one Ge(3) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ge(1) and one Ge(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to two equivalent Ge(2) atoms. 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(3) and one Ge(4) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Ge(1) and one Ge(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(4) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Ge(2) and one N(1) atom.