Zn4Ga2S7 crystallizes in the monoclinic P2_1/m space group. There are four inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 4-coordinate geometry to four equivalent S(2) atoms. In the second Zn site, Zn(2) is bonded to one S(3), one S(4), and two equivalent S(2) atoms to form ZnS4 trigonal pyramids that share corners with three equivalent Ga(2)S4 tetrahedra and  an edgeedge with one Ga(1)S4 tetrahedra. In the third Zn site, Zn(3) is bonded in a 4-coordinate geometry to four equivalent S(1) atoms. In the fourth Zn site, Zn(4) is bonded in a bent 150 degrees geometry to one S(4) and one S(5) atom. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one S(3), one S(4), and two equivalent S(1) atoms to form distorted GaS4 tetrahedra that share  a cornercorner with one Ga(2)S4 tetrahedra and  an edgeedge with one Zn(2)S4 trigonal pyramid. In the second Ga site, Ga(2) is bonded to one S(3), one S(5), and two equivalent S(2) atoms to form GaS4 tetrahedra that share  a cornercorner with one Ga(1)S4 tetrahedra and corners with three equivalent Zn(2)S4 trigonal pyramids. There are five inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to two equivalent Zn(3) and one Ga(1) atom. In the second S site, S(2) is bonded in a distorted see-saw-like geometry to one Zn(2), two equivalent Zn(1), and one Ga(2) atom. In the third S site, S(3) is bonded in a T-shaped geometry to one Zn(2), one Ga(1), and one Ga(2) atom. In the fourth S site, S(4) is bonded in a distorted T-shaped geometry to one Zn(2), one Zn(4), and one Ga(1) atom. In the fifth S site, S(5) is bonded in a distorted L-shaped geometry to one Zn(4) and one Ga(2) atom.
Zn4Ga2S7 crystallizes in the monoclinic P2_1/m space group. There are four inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 4-coordinate geometry to four equivalent S(2) atoms. There are two shorter (2.42 Å) and two longer (2.87 Å) Zn(1)-S(2) bond lengths. In the second Zn site, Zn(2) is bonded to one S(3), one S(4), and two equivalent S(2) atoms to form ZnS4 trigonal pyramids that share corners with three equivalent Ga(2)S4 tetrahedra and  an edgeedge with one Ga(1)S4 tetrahedra. The Zn(2)-S(3) bond length is 2.42 Å. The Zn(2)-S(4) bond length is 2.38 Å. Both Zn(2)-S(2) bond lengths are 2.35 Å. In the third Zn site, Zn(3) is bonded in a 4-coordinate geometry to four equivalent S(1) atoms. There are two shorter (2.48 Å) and two longer (2.52 Å) Zn(3)-S(1) bond lengths. In the fourth Zn site, Zn(4) is bonded in a bent 150 degrees geometry to one S(4) and one S(5) atom. The Zn(4)-S(4) bond length is 2.14 Å. The Zn(4)-S(5) bond length is 2.16 Å. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one S(3), one S(4), and two equivalent S(1) atoms to form distorted GaS4 tetrahedra that share  a cornercorner with one Ga(2)S4 tetrahedra and  an edgeedge with one Zn(2)S4 trigonal pyramid. The Ga(1)-S(3) bond length is 2.30 Å. The Ga(1)-S(4) bond length is 2.28 Å. Both Ga(1)-S(1) bond lengths are 2.30 Å. In the second Ga site, Ga(2) is bonded to one S(3), one S(5), and two equivalent S(2) atoms to form GaS4 tetrahedra that share  a cornercorner with one Ga(1)S4 tetrahedra and corners with three equivalent Zn(2)S4 trigonal pyramids. The Ga(2)-S(3) bond length is 2.29 Å. The Ga(2)-S(5) bond length is 2.25 Å. Both Ga(2)-S(2) bond lengths are 2.35 Å. There are five inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to two equivalent Zn(3) and one Ga(1) atom. In the second S site, S(2) is bonded in a distorted see-saw-like geometry to one Zn(2), two equivalent Zn(1), and one Ga(2) atom. In the third S site, S(3) is bonded in a T-shaped geometry to one Zn(2), one Ga(1), and one Ga(2) atom. In the fourth S site, S(4) is bonded in a distorted T-shaped geometry to one Zn(2), one Zn(4), and one Ga(1) atom. In the fifth S site, S(5) is bonded in a distorted L-shaped geometry to one Zn(4) and one Ga(2) atom.