Fe5(GeO4)3 crystallizes in the tetragonal I-42d space group. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, edges with two equivalent Fe(2)O6 octahedra, and  an edgeedge with one Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with four equivalent Ge(1)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 59°. In the third Fe site, Fe(3) is bonded in a 4-coordinate geometry to four equivalent O(3) atoms. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted GeO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-57°. In the second Ge site, Ge(2) is bonded to four equivalent O(2) atoms to form GeO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra and corners with four equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one Ge(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Ge(2) atom. In the third O site, O(3) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Ge(1) atom to form a mixture of corner and edge-sharing OFe3Ge tetrahedra.
Fe5(GeO4)3 crystallizes in the tetragonal I-42d space group. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, edges with two equivalent Fe(2)O6 octahedra, and  an edgeedge with one Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. Both Fe(1)-O(1) bond lengths are 2.00 Å. Both Fe(1)-O(2) bond lengths are 1.98 Å. Both Fe(1)-O(3) bond lengths are 2.16 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with four equivalent Ge(1)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 59°. Both Fe(2)-O(1) bond lengths are 2.23 Å. Both Fe(2)-O(2) bond lengths are 2.10 Å. Both Fe(2)-O(3) bond lengths are 2.16 Å. In the third Fe site, Fe(3) is bonded in a 4-coordinate geometry to four equivalent O(3) atoms. All Fe(3)-O(3) bond lengths are 2.18 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted GeO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-57°. Both Ge(1)-O(1) bond lengths are 1.76 Å. Both Ge(1)-O(3) bond lengths are 1.82 Å. In the second Ge site, Ge(2) is bonded to four equivalent O(2) atoms to form GeO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra and corners with four equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. All Ge(2)-O(2) bond lengths are 1.78 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one Ge(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Ge(2) atom. In the third O site, O(3) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Ge(1) atom to form a mixture of corner and edge-sharing OFe3Ge tetrahedra.