FeGeO3 crystallizes in the monoclinic C2/c space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with six equivalent Ge(1)O4 tetrahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with three equivalent Fe(2)O6 octahedra. 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 eight equivalent Ge(1)O4 tetrahedra and edges with three equivalent Fe(1)O6 octahedra. Ge(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form GeO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra, and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-62°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Fe(2), two equivalent Fe(1), 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(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Ge(1) atoms.
FeGeO3 crystallizes in the monoclinic C2/c space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with six equivalent Ge(1)O4 tetrahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with three equivalent Fe(2)O6 octahedra. Both Fe(1)-O(2) bond lengths are 2.10 Å. There are two shorter (2.12 Å) and two longer (2.14 Å) Fe(1)-O(1) bond lengths. 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 eight equivalent Ge(1)O4 tetrahedra and edges with three equivalent Fe(1)O6 octahedra. Both Fe(2)-O(1) bond lengths are 2.14 Å. Both Fe(2)-O(2) bond lengths are 2.01 Å. Both Fe(2)-O(3) bond lengths are 2.29 Å. Ge(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form GeO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra, and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-62°. The Ge(1)-O(1) bond length is 1.75 Å. The Ge(1)-O(2) bond length is 1.73 Å. Both Ge(1)-O(3) bond lengths are 1.80 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Fe(2), two equivalent Fe(1), 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(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Ge(1) atoms.