FeGeS3 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 S(3) and four equivalent S(1) atoms to form FeS6 octahedra that share corners with six equivalent Ge(1)S4 tetrahedra, edges with two equivalent Fe(1)S6 octahedra, and edges with three equivalent Fe(2)S6 octahedra. In the second Fe site, Fe(2) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form FeS6 octahedra that share corners with eight equivalent Ge(1)S4 tetrahedra and edges with three equivalent Fe(1)S6 octahedra. Ge(1) is bonded to one S(1), one S(3), and two equivalent S(2) atoms to form GeS4 tetrahedra that share corners with three equivalent Fe(1)S6 octahedra, corners with four equivalent Fe(2)S6 octahedra, and corners with two equivalent Ge(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-68°. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Fe(2), two equivalent Fe(1), and one Ge(1) atom to form a mixture of corner and edge-sharing SFe3Ge tetrahedra. In the second S site, S(2) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Ge(1) atoms. In the third S site, S(3) is bonded in a trigonal non-coplanar geometry to one Fe(1), one Fe(2), and one Ge(1) atom.
FeGeS3 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 S(3) and four equivalent S(1) atoms to form FeS6 octahedra that share corners with six equivalent Ge(1)S4 tetrahedra, edges with two equivalent Fe(1)S6 octahedra, and edges with three equivalent Fe(2)S6 octahedra. Both Fe(1)-S(3) bond lengths are 2.27 Å. All Fe(1)-S(1) bond lengths are 2.29 Å. In the second Fe site, Fe(2) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form FeS6 octahedra that share corners with eight equivalent Ge(1)S4 tetrahedra and edges with three equivalent Fe(1)S6 octahedra. Both Fe(2)-S(1) bond lengths are 2.25 Å. Both Fe(2)-S(2) bond lengths are 2.31 Å. Both Fe(2)-S(3) bond lengths are 2.29 Å. Ge(1) is bonded to one S(1), one S(3), and two equivalent S(2) atoms to form GeS4 tetrahedra that share corners with three equivalent Fe(1)S6 octahedra, corners with four equivalent Fe(2)S6 octahedra, and corners with two equivalent Ge(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-68°. The Ge(1)-S(1) bond length is 2.43 Å. The Ge(1)-S(3) bond length is 2.32 Å. There is one shorter (2.30 Å) and one longer (2.33 Å) Ge(1)-S(2) bond length. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Fe(2), two equivalent Fe(1), and one Ge(1) atom to form a mixture of corner and edge-sharing SFe3Ge tetrahedra. In the second S site, S(2) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Ge(1) atoms. In the third S site, S(3) is bonded in a trigonal non-coplanar geometry to one Fe(1), one Fe(2), and one Ge(1) atom.