Mg2GeS4 is Spinel-like structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form MgS6 octahedra that share corners with four equivalent Mg(2)S6 octahedra, corners with two equivalent Ge(1)S4 tetrahedra, edges with two equivalent Mg(1)S6 octahedra, edges with two equivalent Mg(2)S6 octahedra, and edges with two equivalent Ge(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-57°. In the second Mg site, Mg(2) is bonded to one S(1), one S(3), and four equivalent S(2) atoms to form MgS6 octahedra that share corners with four equivalent Mg(1)S6 octahedra, corners with four equivalent Mg(2)S6 octahedra, corners with four equivalent Ge(1)S4 tetrahedra, edges with two equivalent Mg(1)S6 octahedra, and  an edgeedge with one Ge(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-57°. 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 two equivalent Mg(1)S6 octahedra, corners with four equivalent Mg(2)S6 octahedra,  an edgeedge with one Mg(2)S6 octahedra, and edges with two equivalent Mg(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 59-61°. There are three inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Mg(2), two equivalent Mg(1), and one Ge(1) atom. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), two equivalent Mg(2), and one Ge(1) atom. In the third S site, S(3) is bonded to one Mg(2), two equivalent Mg(1), and one Ge(1) atom to form distorted corner-sharing SMg3Ge trigonal pyramids.
Mg2GeS4 is Spinel-like structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form MgS6 octahedra that share corners with four equivalent Mg(2)S6 octahedra, corners with two equivalent Ge(1)S4 tetrahedra, edges with two equivalent Mg(1)S6 octahedra, edges with two equivalent Mg(2)S6 octahedra, and edges with two equivalent Ge(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-57°. Both Mg(1)-S(1) bond lengths are 2.57 Å. Both Mg(1)-S(2) bond lengths are 2.62 Å. Both Mg(1)-S(3) bond lengths are 2.59 Å. In the second Mg site, Mg(2) is bonded to one S(1), one S(3), and four equivalent S(2) atoms to form MgS6 octahedra that share corners with four equivalent Mg(1)S6 octahedra, corners with four equivalent Mg(2)S6 octahedra, corners with four equivalent Ge(1)S4 tetrahedra, edges with two equivalent Mg(1)S6 octahedra, and  an edgeedge with one Ge(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-57°. The Mg(2)-S(1) bond length is 2.56 Å. The Mg(2)-S(3) bond length is 2.63 Å. There are two shorter (2.62 Å) and two longer (2.66 Å) Mg(2)-S(2) bond lengths. 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 two equivalent Mg(1)S6 octahedra, corners with four equivalent Mg(2)S6 octahedra,  an edgeedge with one Mg(2)S6 octahedra, and edges with two equivalent Mg(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 59-61°. The Ge(1)-S(1) bond length is 2.23 Å. The Ge(1)-S(3) bond length is 2.19 Å. Both Ge(1)-S(2) bond lengths are 2.23 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Mg(2), two equivalent Mg(1), and one Ge(1) atom. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), two equivalent Mg(2), and one Ge(1) atom. In the third S site, S(3) is bonded to one Mg(2), two equivalent Mg(1), and one Ge(1) atom to form distorted corner-sharing SMg3Ge trigonal pyramids.