Mg2W3AlS8 is Bixbyite (Mn,Fe)2O4-derived structured and crystallizes in the triclinic P1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one S(1), one S(5), one S(6), and one S(8) atom to form MgS4 tetrahedra that share corners with three equivalent Al(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 54-58°. In the second Mg site, Mg(2) is bonded to one S(2), one S(3), one S(4), and one S(7) atom to form distorted MgS4 tetrahedra that share corners with three equivalent Al(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 66-67°. There are three inequivalent W sites. In the first W site, W(1) is bonded in a 6-coordinate geometry to one S(1), one S(3), one S(4), one S(5), one S(6), and one S(7) atom. In the second W site, W(2) is bonded in a 6-coordinate geometry to one S(1), one S(2), one S(3), one S(5), one S(7), and one S(8) atom. In the third W site, W(3) is bonded in a 6-coordinate geometry to one S(1), one S(2), one S(4), one S(6), one S(7), and one S(8) atom. Al(1) is bonded to one S(2), one S(3), one S(4), one S(5), one S(6), and one S(8) atom to form AlS6 octahedra that share corners with three equivalent Mg(1)S4 tetrahedra and corners with three equivalent Mg(2)S4 tetrahedra. There are eight inequivalent S sites. In the first S site, S(1) is bonded in a 4-coordinate geometry to one Mg(1), one W(1), one W(2), and one W(3) atom. In the second S site, S(2) is bonded to one Mg(2), one W(2), one W(3), and one Al(1) atom to form distorted SMgAlW2 tetrahedra that share  a cornercorner with one S(4)MgAlW2 tetrahedra,  a cornercorner with one S(7)MgW3 tetrahedra,  an edgeedge with one S(4)MgAlW2 tetrahedra, and  an edgeedge with one S(7)MgW3 tetrahedra. In the third S site, S(3) is bonded in a 4-coordinate geometry to one Mg(2), one W(1), one W(2), and one Al(1) atom. In the fourth S site, S(4) is bonded to one Mg(2), one W(1), one W(3), and one Al(1) atom to form distorted SMgAlW2 tetrahedra that share  a cornercorner with one S(2)MgAlW2 tetrahedra,  a cornercorner with one S(7)MgW3 tetrahedra,  an edgeedge with one S(2)MgAlW2 tetrahedra, and  an edgeedge with one S(7)MgW3 tetrahedra. In the fifth S site, S(5) is bonded in a 4-coordinate geometry to one Mg(1), one W(1), one W(2), and one Al(1) atom. In the sixth S site, S(6) is bonded in a 4-coordinate geometry to one Mg(1), one W(1), one W(3), and one Al(1) atom. In the seventh S site, S(7) is bonded to one Mg(2), one W(1), one W(2), and one W(3) atom to form a mixture of distorted corner and edge-sharing SMgW3 tetrahedra. In the eighth S site, S(8) is bonded in a 4-coordinate geometry to one Mg(1), one W(2), one W(3), and one Al(1) atom.
Mg2W3AlS8 is Bixbyite (Mn,Fe)2O4-derived structured and crystallizes in the triclinic P1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one S(1), one S(5), one S(6), and one S(8) atom to form MgS4 tetrahedra that share corners with three equivalent Al(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 54-58°. The Mg(1)-S(1) bond length is 2.46 Å. The Mg(1)-S(5) bond length is 2.34 Å. The Mg(1)-S(6) bond length is 2.34 Å. The Mg(1)-S(8) bond length is 2.34 Å. In the second Mg site, Mg(2) is bonded to one S(2), one S(3), one S(4), and one S(7) atom to form distorted MgS4 tetrahedra that share corners with three equivalent Al(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 66-67°. The Mg(2)-S(2) bond length is 2.46 Å. The Mg(2)-S(3) bond length is 2.46 Å. The Mg(2)-S(4) bond length is 2.46 Å. The Mg(2)-S(7) bond length is 2.49 Å. There are three inequivalent W sites. In the first W site, W(1) is bonded in a 6-coordinate geometry to one S(1), one S(3), one S(4), one S(5), one S(6), and one S(7) atom. The W(1)-S(1) bond length is 2.36 Å. The W(1)-S(3) bond length is 2.61 Å. The W(1)-S(4) bond length is 2.58 Å. The W(1)-S(5) bond length is 2.40 Å. The W(1)-S(6) bond length is 2.37 Å. The W(1)-S(7) bond length is 2.68 Å. In the second W site, W(2) is bonded in a 6-coordinate geometry to one S(1), one S(2), one S(3), one S(5), one S(7), and one S(8) atom. The W(2)-S(1) bond length is 2.36 Å. The W(2)-S(2) bond length is 2.58 Å. The W(2)-S(3) bond length is 2.61 Å. The W(2)-S(5) bond length is 2.40 Å. The W(2)-S(7) bond length is 2.68 Å. The W(2)-S(8) bond length is 2.37 Å. In the third W site, W(3) is bonded in a 6-coordinate geometry to one S(1), one S(2), one S(4), one S(6), one S(7), and one S(8) atom. The W(3)-S(1) bond length is 2.37 Å. The W(3)-S(2) bond length is 2.57 Å. The W(3)-S(4) bond length is 2.57 Å. The W(3)-S(6) bond length is 2.40 Å. The W(3)-S(7) bond length is 2.64 Å. The W(3)-S(8) bond length is 2.40 Å. Al(1) is bonded to one S(2), one S(3), one S(4), one S(5), one S(6), and one S(8) atom to form AlS6 octahedra that share corners with three equivalent Mg(1)S4 tetrahedra and corners with three equivalent Mg(2)S4 tetrahedra. The Al(1)-S(2) bond length is 2.38 Å. The Al(1)-S(3) bond length is 2.39 Å. The Al(1)-S(4) bond length is 2.38 Å. The Al(1)-S(5) bond length is 2.50 Å. The Al(1)-S(6) bond length is 2.51 Å. The Al(1)-S(8) bond length is 2.51 Å. There are eight inequivalent S sites. In the first S site, S(1) is bonded in a 4-coordinate geometry to one Mg(1), one W(1), one W(2), and one W(3) atom. In the second S site, S(2) is bonded to one Mg(2), one W(2), one W(3), and one Al(1) atom to form distorted SMgAlW2 tetrahedra that share  a cornercorner with one S(4)MgAlW2 tetrahedra,  a cornercorner with one S(7)MgW3 tetrahedra,  an edgeedge with one S(4)MgAlW2 tetrahedra, and  an edgeedge with one S(7)MgW3 tetrahedra. In the third S site, S(3) is bonded in a 4-coordinate geometry to one Mg(2), one W(1), one W(2), and one Al(1) atom. In the fourth S site, S(4) is bonded to one Mg(2), one W(1), one W(3), and one Al(1) atom to form distorted SMgAlW2 tetrahedra that share  a cornercorner with one S(2)MgAlW2 tetrahedra,  a cornercorner with one S(7)MgW3 tetrahedra,  an edgeedge with one S(2)MgAlW2 tetrahedra, and  an edgeedge with one S(7)MgW3 tetrahedra. In the fifth S site, S(5) is bonded in a 4-coordinate geometry to one Mg(1), one W(1), one W(2), and one Al(1) atom. In the sixth S site, S(6) is bonded in a 4-coordinate geometry to one Mg(1), one W(1), one W(3), and one Al(1) atom. In the seventh S site, S(7) is bonded to one Mg(2), one W(1), one W(2), and one W(3) atom to form a mixture of distorted corner and edge-sharing SMgW3 tetrahedra. In the eighth S site, S(8) is bonded in a 4-coordinate geometry to one Mg(1), one W(2), one W(3), and one Al(1) atom.