In2Ge2O7 crystallizes in the monoclinic C2/m space group. In(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form distorted InO6 pentagonal pyramids that share corners with six equivalent Ge(1)O4 tetrahedra and edges with three equivalent In(1)O6 pentagonal pyramids. 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 six equivalent In(1)O6 pentagonal pyramids and  a cornercorner with one Ge(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent In(1) and one Ge(1) atom. In the second O site, O(2) is bonded in a linear geometry to two equivalent Ge(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent In(1) and one Ge(1) atom.
In2Ge2O7 crystallizes in the monoclinic C2/m space group. In(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form distorted InO6 pentagonal pyramids that share corners with six equivalent Ge(1)O4 tetrahedra and edges with three equivalent In(1)O6 pentagonal pyramids. Both In(1)-O(3) bond lengths are 2.18 Å. There are two shorter (2.13 Å) and two longer (2.23 Å) In(1)-O(1) bond lengths. 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 six equivalent In(1)O6 pentagonal pyramids and  a cornercorner with one Ge(1)O4 tetrahedra. The Ge(1)-O(2) bond length is 1.73 Å. The Ge(1)-O(3) bond length is 1.76 Å. Both Ge(1)-O(1) bond lengths are 1.76 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent In(1) and one Ge(1) atom. In the second O site, O(2) is bonded in a linear geometry to two equivalent Ge(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent In(1) and one Ge(1) atom.