K6Mg(SbS4)2 crystallizes in the triclinic P1 space group. There are six inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one S(1), one S(2), one S(4), one S(5), one S(7), and one S(8) atom. In the second K site, K(2) is bonded in a 4-coordinate geometry to one S(1), one S(2), one S(6), and one S(8) atom. In the third K site, K(3) is bonded in a 6-coordinate geometry to one S(2), one S(3), one S(4), one S(5), one S(6), and one S(7) atom. In the fourth K site, K(4) is bonded in a distorted square co-planar geometry to one S(1), one S(4), one S(5), and one S(7) atom. In the fifth K site, K(5) is bonded in a 6-coordinate geometry to one S(1), one S(2), one S(3), one S(4), one S(6), and one S(8) atom. In the sixth K site, K(6) is bonded in a 5-coordinate geometry to one Sb(2), one S(1), one S(3), one S(4), and one S(8) atom. Mg(1) is bonded to one S(1), one S(3), one S(5), and one S(6) atom to form distorted MgS4 trigonal pyramids that share  a cornercorner with one Sb(1)S4 tetrahedra. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one S(2), one S(4), one S(6), and one S(8) atom to form SbS4 tetrahedra that share  a cornercorner with one Mg(1)S4 trigonal pyramid. In the second Sb site, Sb(2) is bonded in a 3-coordinate geometry to one K(6), one S(3), one S(5), and one S(7) atom. There are eight inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to one K(1), one K(2), one K(4), one K(5), one K(6), and one Mg(1) atom. In the second S site, S(2) is bonded to one K(1), one K(2), one K(3), one K(5), and one Sb(1) atom to form distorted edge-sharing SK4Sb trigonal bipyramids. In the third S site, S(3) is bonded in a 5-coordinate geometry to one K(3), one K(5), one K(6), one Mg(1), and one Sb(2) atom. In the fourth S site, S(4) is bonded in a 6-coordinate geometry to one K(1), one K(3), one K(4), one K(5), one K(6), and one Sb(1) atom. In the fifth S site, S(5) is bonded to one K(1), one K(3), one K(4), one Mg(1), and one Sb(2) atom to form distorted edge-sharing SK3MgSb trigonal bipyramids. In the sixth S site, S(6) is bonded in a 5-coordinate geometry to one K(2), one K(3), one K(5), one Mg(1), and one Sb(1) atom. In the seventh S site, S(7) is bonded in a distorted see-saw-like geometry to one K(1), one K(3), one K(4), and one Sb(2) atom. In the eighth S site, S(8) is bonded in a 5-coordinate geometry to one K(1), one K(2), one K(5), one K(6), and one Sb(1) atom.
K6Mg(SbS4)2 crystallizes in the triclinic P1 space group. There are six inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one S(1), one S(2), one S(4), one S(5), one S(7), and one S(8) atom. The K(1)-S(1) bond length is 3.10 Å. The K(1)-S(2) bond length is 3.14 Å. The K(1)-S(4) bond length is 3.32 Å. The K(1)-S(5) bond length is 3.24 Å. The K(1)-S(7) bond length is 3.17 Å. The K(1)-S(8) bond length is 3.37 Å. In the second K site, K(2) is bonded in a 4-coordinate geometry to one S(1), one S(2), one S(6), and one S(8) atom. The K(2)-S(1) bond length is 3.08 Å. The K(2)-S(2) bond length is 3.45 Å. The K(2)-S(6) bond length is 3.68 Å. The K(2)-S(8) bond length is 3.15 Å. In the third K site, K(3) is bonded in a 6-coordinate geometry to one S(2), one S(3), one S(4), one S(5), one S(6), and one S(7) atom. The K(3)-S(2) bond length is 3.41 Å. The K(3)-S(3) bond length is 3.50 Å. The K(3)-S(4) bond length is 3.37 Å. The K(3)-S(5) bond length is 3.20 Å. The K(3)-S(6) bond length is 3.33 Å. The K(3)-S(7) bond length is 3.23 Å. In the fourth K site, K(4) is bonded in a distorted square co-planar geometry to one S(1), one S(4), one S(5), and one S(7) atom. The K(4)-S(1) bond length is 3.25 Å. The K(4)-S(4) bond length is 3.47 Å. The K(4)-S(5) bond length is 3.17 Å. The K(4)-S(7) bond length is 3.32 Å. In the fifth K site, K(5) is bonded in a 6-coordinate geometry to one S(1), one S(2), one S(3), one S(4), one S(6), and one S(8) atom. The K(5)-S(1) bond length is 3.49 Å. The K(5)-S(2) bond length is 3.25 Å. The K(5)-S(3) bond length is 3.26 Å. The K(5)-S(4) bond length is 3.67 Å. The K(5)-S(6) bond length is 3.40 Å. The K(5)-S(8) bond length is 3.24 Å. In the sixth K site, K(6) is bonded in a 5-coordinate geometry to one Sb(2), one S(1), one S(3), one S(4), and one S(8) atom. The K(6)-Sb(2) bond length is 3.58 Å. The K(6)-S(1) bond length is 3.09 Å. The K(6)-S(3) bond length is 3.24 Å. The K(6)-S(4) bond length is 3.45 Å. The K(6)-S(8) bond length is 3.44 Å. Mg(1) is bonded to one S(1), one S(3), one S(5), and one S(6) atom to form distorted MgS4 trigonal pyramids that share  a cornercorner with one Sb(1)S4 tetrahedra. The Mg(1)-S(1) bond length is 2.38 Å. The Mg(1)-S(3) bond length is 2.54 Å. The Mg(1)-S(5) bond length is 2.52 Å. The Mg(1)-S(6) bond length is 2.55 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one S(2), one S(4), one S(6), and one S(8) atom to form SbS4 tetrahedra that share  a cornercorner with one Mg(1)S4 trigonal pyramid. The Sb(1)-S(2) bond length is 2.37 Å. The Sb(1)-S(4) bond length is 2.38 Å. The Sb(1)-S(6) bond length is 2.41 Å. The Sb(1)-S(8) bond length is 2.37 Å. In the second Sb site, Sb(2) is bonded in a 3-coordinate geometry to one K(6), one S(3), one S(5), and one S(7) atom. The Sb(2)-S(3) bond length is 2.49 Å. The Sb(2)-S(5) bond length is 2.45 Å. The Sb(2)-S(7) bond length is 2.42 Å. There are eight inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to one K(1), one K(2), one K(4), one K(5), one K(6), and one Mg(1) atom. In the second S site, S(2) is bonded to one K(1), one K(2), one K(3), one K(5), and one Sb(1) atom to form distorted edge-sharing SK4Sb trigonal bipyramids. In the third S site, S(3) is bonded in a 5-coordinate geometry to one K(3), one K(5), one K(6), one Mg(1), and one Sb(2) atom. In the fourth S site, S(4) is bonded in a 6-coordinate geometry to one K(1), one K(3), one K(4), one K(5), one K(6), and one Sb(1) atom. In the fifth S site, S(5) is bonded to one K(1), one K(3), one K(4), one Mg(1), and one Sb(2) atom to form distorted edge-sharing SK3MgSb trigonal bipyramids. In the sixth S site, S(6) is bonded in a 5-coordinate geometry to one K(2), one K(3), one K(5), one Mg(1), and one Sb(1) atom. In the seventh S site, S(7) is bonded in a distorted see-saw-like geometry to one K(1), one K(3), one K(4), and one Sb(2) atom. In the eighth S site, S(8) is bonded in a 5-coordinate geometry to one K(1), one K(2), one K(5), one K(6), and one Sb(1) atom.