Mg3Fe4(WO4)6 crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. In the second Mg site, Mg(2) is bonded to one O(11), one O(2), one O(5), one O(6), and one O(7) atom to form MgO5 trigonal bipyramids that share  a cornercorner with one W(2)O4 tetrahedra, corners with two equivalent W(1)O4 tetrahedra, corners with two equivalent W(3)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Fe(2)O6 octahedra. There are three inequivalent W sites. In the first W site, W(1) is bonded to one O(10), one O(11), one O(3), and one O(6) atom to form WO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Mg(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 20-69°. In the second W site, W(2) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form WO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and  a cornercorner with one Mg(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 44-56°. In the third W site, W(3) is bonded to one O(12), one O(2), one O(5), and one O(9) atom to form WO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Mg(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 22-57°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(6), one O(7), one O(9), and two equivalent O(4) atoms to form FeO6 octahedra that share  a cornercorner with one W(3)O4 tetrahedra, corners with two equivalent W(1)O4 tetrahedra, corners with three equivalent W(2)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Mg(2)O5 trigonal bipyramid. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(12), one O(5), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent W(1)O4 tetrahedra, corners with two equivalent W(2)O4 tetrahedra, corners with two equivalent W(3)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Mg(2)O5 trigonal bipyramid. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mg(1) and one W(2) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Mg(2) and one W(3) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mg(1), one W(1), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one W(2) and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mg(2), one W(3), and one Fe(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(2), one W(1), and one Fe(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Mg(2), one W(2), and one Fe(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one W(2) and two equivalent Fe(2) atoms. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one W(3) and one Fe(1) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one W(1) and one Fe(2) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Mg(2), one W(1), and one Fe(2) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one W(3) and one Fe(2) atom.
Mg3Fe4(WO4)6 crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. Both Mg(1)-O(1) bond lengths are 1.96 Å. Both Mg(1)-O(3) bond lengths are 2.15 Å. In the second Mg site, Mg(2) is bonded to one O(11), one O(2), one O(5), one O(6), and one O(7) atom to form MgO5 trigonal bipyramids that share  a cornercorner with one W(2)O4 tetrahedra, corners with two equivalent W(1)O4 tetrahedra, corners with two equivalent W(3)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Fe(2)O6 octahedra. The Mg(2)-O(11) bond length is 2.16 Å. The Mg(2)-O(2) bond length is 2.01 Å. The Mg(2)-O(5) bond length is 2.04 Å. The Mg(2)-O(6) bond length is 2.08 Å. The Mg(2)-O(7) bond length is 1.98 Å. There are three inequivalent W sites. In the first W site, W(1) is bonded to one O(10), one O(11), one O(3), and one O(6) atom to form WO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Mg(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 20-69°. The W(1)-O(10) bond length is 1.79 Å. The W(1)-O(11) bond length is 1.85 Å. The W(1)-O(3) bond length is 1.83 Å. The W(1)-O(6) bond length is 1.83 Å. In the second W site, W(2) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form WO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and  a cornercorner with one Mg(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 44-56°. The W(2)-O(1) bond length is 1.83 Å. The W(2)-O(4) bond length is 1.92 Å. The W(2)-O(7) bond length is 1.92 Å. The W(2)-O(8) bond length is 1.89 Å. In the third W site, W(3) is bonded to one O(12), one O(2), one O(5), and one O(9) atom to form WO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Mg(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 22-57°. The W(3)-O(12) bond length is 1.79 Å. The W(3)-O(2) bond length is 1.83 Å. The W(3)-O(5) bond length is 1.86 Å. The W(3)-O(9) bond length is 1.80 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(6), one O(7), one O(9), and two equivalent O(4) atoms to form FeO6 octahedra that share  a cornercorner with one W(3)O4 tetrahedra, corners with two equivalent W(1)O4 tetrahedra, corners with three equivalent W(2)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Mg(2)O5 trigonal bipyramid. The Fe(1)-O(3) bond length is 2.45 Å. The Fe(1)-O(6) bond length is 2.30 Å. The Fe(1)-O(7) bond length is 2.07 Å. The Fe(1)-O(9) bond length is 2.10 Å. There is one shorter (2.11 Å) and one longer (2.14 Å) Fe(1)-O(4) bond length. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(12), one O(5), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent W(1)O4 tetrahedra, corners with two equivalent W(2)O4 tetrahedra, corners with two equivalent W(3)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Mg(2)O5 trigonal bipyramid. The Fe(2)-O(10) bond length is 2.15 Å. The Fe(2)-O(11) bond length is 2.17 Å. The Fe(2)-O(12) bond length is 2.10 Å. The Fe(2)-O(5) bond length is 2.29 Å. There is one shorter (2.06 Å) and one longer (2.15 Å) Fe(2)-O(8) bond length. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mg(1) and one W(2) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Mg(2) and one W(3) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mg(1), one W(1), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one W(2) and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mg(2), one W(3), and one Fe(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(2), one W(1), and one Fe(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Mg(2), one W(2), and one Fe(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one W(2) and two equivalent Fe(2) atoms. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one W(3) and one Fe(1) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one W(1) and one Fe(2) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Mg(2), one W(1), and one Fe(2) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one W(3) and one Fe(2) atom.