MgFe2S2(O4F)2 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent F(1) atoms to form MgO4F2 octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with four equivalent S(1)O4 tetrahedra, and faces with two equivalent Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles are 43°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent F(1) atoms to form FeO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with two equivalent Fe(2)O4F2 octahedra, and corners with four equivalent S(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-53°. In the second Fe site, Fe(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent F(1) atoms to form distorted FeO4F2 octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with four equivalent S(1)O4 tetrahedra, and faces with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles are 53°. S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with two equivalent Fe(1)O4F2 octahedra, and corners with two equivalent Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 31-49°. There are four 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 bent 150 degrees geometry to one Fe(1) and one S(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(2), 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(2), and one S(1) atom. F(1) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom.
MgFe2S2(O4F)2 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent F(1) atoms to form MgO4F2 octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with four equivalent S(1)O4 tetrahedra, and faces with two equivalent Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles are 43°. Both Mg(1)-O(3) bond lengths are 2.11 Å. Both Mg(1)-O(4) bond lengths are 2.08 Å. Both Mg(1)-F(1) bond lengths are 2.00 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent F(1) atoms to form FeO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with two equivalent Fe(2)O4F2 octahedra, and corners with four equivalent S(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-53°. Both Fe(1)-O(1) bond lengths are 2.19 Å. Both Fe(1)-O(2) bond lengths are 2.16 Å. Both Fe(1)-F(1) bond lengths are 2.08 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent F(1) atoms to form distorted FeO4F2 octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with four equivalent S(1)O4 tetrahedra, and faces with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles are 53°. Both Fe(2)-O(3) bond lengths are 2.12 Å. Both Fe(2)-O(4) bond lengths are 2.14 Å. Both Fe(2)-F(1) bond lengths are 2.13 Å. S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with two equivalent Fe(1)O4F2 octahedra, and corners with two equivalent Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 31-49°. The S(1)-O(1) bond length is 1.46 Å. The S(1)-O(2) bond length is 1.46 Å. The S(1)-O(3) bond length is 1.52 Å. The S(1)-O(4) bond length is 1.52 Å. There are four 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 bent 150 degrees geometry to one Fe(1) and one S(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(2), 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(2), and one S(1) atom. F(1) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom.