SnGa2GeS6 crystallizes in the orthorhombic Fdd2 space group. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one S(1), one S(2), one S(5), and one S(6) atom to form GaS4 tetrahedra that share  a cornercorner with one Ge(1)S4 tetrahedra,  a cornercorner with one Ge(2)S4 tetrahedra, and corners with two equivalent Ga(2)S4 tetrahedra. In the second Ga site, Ga(2) is bonded to one S(2), one S(5), and two equivalent S(3) atoms to form corner-sharing GaS4 tetrahedra. Sn(1) is bonded in a rectangular see-saw-like geometry to one S(1), one S(3), one S(5), and one S(6) atom. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to two equivalent S(4) and two equivalent S(6) atoms to form GeS4 tetrahedra that share corners with two equivalent Ga(1)S4 tetrahedra and corners with two equivalent Ge(2)S4 tetrahedra. In the second Ge site, Ge(2) is bonded to two equivalent S(1) and two equivalent S(4) atoms to form GeS4 tetrahedra that share corners with two equivalent Ga(1)S4 tetrahedra and corners with two equivalent Ge(1)S4 tetrahedra. There are six inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to one Ga(1), one Sn(1), and one Ge(2) atom. In the second S site, S(2) is bonded in a water-like geometry to one Ga(1) and one Ga(2) atom. In the third S site, S(3) is bonded in a distorted T-shaped geometry to two equivalent Ga(2) and one Sn(1) atom. In the fourth S site, S(4) is bonded in a water-like geometry to one Ge(1) and one Ge(2) atom. In the fifth S site, S(5) is bonded in a distorted water-like geometry to one Ga(1), one Ga(2), and one Sn(1) atom. In the sixth S site, S(6) is bonded in a distorted trigonal non-coplanar geometry to one Ga(1), one Sn(1), and one Ge(1) atom.
SnGa2GeS6 crystallizes in the orthorhombic Fdd2 space group. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one S(1), one S(2), one S(5), and one S(6) atom to form GaS4 tetrahedra that share  a cornercorner with one Ge(1)S4 tetrahedra,  a cornercorner with one Ge(2)S4 tetrahedra, and corners with two equivalent Ga(2)S4 tetrahedra. The Ga(1)-S(1) bond length is 2.38 Å. The Ga(1)-S(2) bond length is 2.21 Å. The Ga(1)-S(5) bond length is 2.26 Å. The Ga(1)-S(6) bond length is 2.32 Å. In the second Ga site, Ga(2) is bonded to one S(2), one S(5), and two equivalent S(3) atoms to form corner-sharing GaS4 tetrahedra. The Ga(2)-S(2) bond length is 2.27 Å. The Ga(2)-S(5) bond length is 2.28 Å. There is one shorter (2.31 Å) and one longer (2.32 Å) Ga(2)-S(3) bond length. Sn(1) is bonded in a rectangular see-saw-like geometry to one S(1), one S(3), one S(5), and one S(6) atom. The Sn(1)-S(1) bond length is 2.81 Å. The Sn(1)-S(3) bond length is 2.85 Å. The Sn(1)-S(5) bond length is 2.99 Å. The Sn(1)-S(6) bond length is 3.02 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to two equivalent S(4) and two equivalent S(6) atoms to form GeS4 tetrahedra that share corners with two equivalent Ga(1)S4 tetrahedra and corners with two equivalent Ge(2)S4 tetrahedra. Both Ge(1)-S(4) bond lengths are 2.31 Å. Both Ge(1)-S(6) bond lengths are 2.22 Å. In the second Ge site, Ge(2) is bonded to two equivalent S(1) and two equivalent S(4) atoms to form GeS4 tetrahedra that share corners with two equivalent Ga(1)S4 tetrahedra and corners with two equivalent Ge(1)S4 tetrahedra. Both Ge(2)-S(1) bond lengths are 2.25 Å. Both Ge(2)-S(4) bond lengths are 2.29 Å. There are six inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to one Ga(1), one Sn(1), and one Ge(2) atom. In the second S site, S(2) is bonded in a water-like geometry to one Ga(1) and one Ga(2) atom. In the third S site, S(3) is bonded in a distorted T-shaped geometry to two equivalent Ga(2) and one Sn(1) atom. In the fourth S site, S(4) is bonded in a water-like geometry to one Ge(1) and one Ge(2) atom. In the fifth S site, S(5) is bonded in a distorted water-like geometry to one Ga(1), one Ga(2), and one Sn(1) atom. In the sixth S site, S(6) is bonded in a distorted trigonal non-coplanar geometry to one Ga(1), one Sn(1), and one Ge(1) atom.