MgFe2S2(O4F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), one O(6), and one F(1) atom to form distorted MgO4F trigonal bipyramids that share corners with two equivalent Fe(2)O4F2 octahedra,  a cornercorner with one S(1)O4 tetrahedra,  a cornercorner with one S(2)O4 tetrahedra, edges with two equivalent Fe(1)O4F2 octahedra, and  an edgeedge with one S(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-56°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one F(1), and one F(2) atom to form FeO4F2 octahedra that share corners with two equivalent Fe(2)O4F2 octahedra, corners with two equivalent S(1)O4 tetrahedra, corners with two equivalent S(2)O4 tetrahedra, and edges with two equivalent Mg(1)O4F trigonal bipyramids. The corner-sharing octahedral tilt angles range from 47-49°. In the second Fe site, Fe(2) is bonded to one O(5), one O(6), one O(7), one O(8), one F(1), and one F(2) atom to form FeO4F2 octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent S(1)O4 tetrahedra, corners with two equivalent S(2)O4 tetrahedra, and corners with two equivalent Mg(1)O4F trigonal bipyramids. The corner-sharing octahedral tilt angles range from 47-49°. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form SO4 tetrahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent Fe(2)O4F2 octahedra, and  a cornercorner with one Mg(1)O4F trigonal bipyramid. The corner-sharing octahedral tilt angles range from 29-55°. In the second S site, S(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form SO4 tetrahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent Fe(2)O4F2 octahedra,  a cornercorner with one Mg(1)O4F trigonal bipyramid, and  an edgeedge with one Mg(1)O4F trigonal bipyramid. The corner-sharing octahedral tilt angles range from 33-56°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one S(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one S(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one S(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one S(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one S(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(2), and one S(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(2) and one S(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Fe(2) and one S(2) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the second F site, F(2) is bonded in a bent 120 degrees geometry to one Fe(1) and one Fe(2) atom.
MgFe2S2(O4F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), one O(6), and one F(1) atom to form distorted MgO4F trigonal bipyramids that share corners with two equivalent Fe(2)O4F2 octahedra,  a cornercorner with one S(1)O4 tetrahedra,  a cornercorner with one S(2)O4 tetrahedra, edges with two equivalent Fe(1)O4F2 octahedra, and  an edgeedge with one S(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-56°. The Mg(1)-O(2) bond length is 2.10 Å. The Mg(1)-O(3) bond length is 2.02 Å. The Mg(1)-O(4) bond length is 2.06 Å. The Mg(1)-O(6) bond length is 2.16 Å. The Mg(1)-F(1) bond length is 1.94 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one F(1), and one F(2) atom to form FeO4F2 octahedra that share corners with two equivalent Fe(2)O4F2 octahedra, corners with two equivalent S(1)O4 tetrahedra, corners with two equivalent S(2)O4 tetrahedra, and edges with two equivalent Mg(1)O4F trigonal bipyramids. The corner-sharing octahedral tilt angles range from 47-49°. The Fe(1)-O(1) bond length is 2.05 Å. The Fe(1)-O(2) bond length is 2.24 Å. The Fe(1)-O(3) bond length is 2.14 Å. The Fe(1)-O(4) bond length is 2.25 Å. The Fe(1)-F(1) bond length is 2.16 Å. The Fe(1)-F(2) bond length is 1.96 Å. In the second Fe site, Fe(2) is bonded to one O(5), one O(6), one O(7), one O(8), one F(1), and one F(2) atom to form FeO4F2 octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent S(1)O4 tetrahedra, corners with two equivalent S(2)O4 tetrahedra, and corners with two equivalent Mg(1)O4F trigonal bipyramids. The corner-sharing octahedral tilt angles range from 47-49°. The Fe(2)-O(5) bond length is 2.12 Å. The Fe(2)-O(6) bond length is 2.35 Å. The Fe(2)-O(7) bond length is 2.20 Å. The Fe(2)-O(8) bond length is 2.21 Å. The Fe(2)-F(1) bond length is 2.10 Å. The Fe(2)-F(2) bond length is 1.96 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form SO4 tetrahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent Fe(2)O4F2 octahedra, and  a cornercorner with one Mg(1)O4F trigonal bipyramid. The corner-sharing octahedral tilt angles range from 29-55°. The S(1)-O(1) bond length is 1.47 Å. The S(1)-O(3) bond length is 1.54 Å. The S(1)-O(5) bond length is 1.47 Å. The S(1)-O(7) bond length is 1.48 Å. In the second S site, S(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form SO4 tetrahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent Fe(2)O4F2 octahedra,  a cornercorner with one Mg(1)O4F trigonal bipyramid, and  an edgeedge with one Mg(1)O4F trigonal bipyramid. The corner-sharing octahedral tilt angles range from 33-56°. The S(2)-O(2) bond length is 1.51 Å. The S(2)-O(4) bond length is 1.51 Å. The S(2)-O(6) bond length is 1.51 Å. The S(2)-O(8) bond length is 1.45 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one S(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one S(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one S(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one S(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one S(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(2), and one S(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(2) and one S(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Fe(2) and one S(2) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the second F site, F(2) is bonded in a bent 120 degrees geometry to one Fe(1) and one Fe(2) atom.