MgW2Cu2(O3F2)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(4), one O(6), two equivalent O(3), and one F(1) atom to form distorted MgO4F trigonal bipyramids that share corners with two equivalent Mg(1)O4F trigonal bipyramids,  an edgeedge with one W(2)O4F2 octahedra, and edges with two equivalent W(1)O4F2 octahedra. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(2), one O(3), two equivalent O(4), one F(2), and one F(3) atom to form WO4F2 octahedra that share corners with two equivalent W(1)O4F2 octahedra and edges with two equivalent Mg(1)O4F trigonal bipyramids. The corner-sharing octahedral tilt angles are 17°. In the second W site, W(2) is bonded to one O(1), one O(6), two equivalent O(5), one F(1), and one F(4) atom to form WO4F2 octahedra that share corners with two equivalent W(2)O4F2 octahedra and  an edgeedge with one Mg(1)O4F trigonal bipyramid. The corner-sharing octahedral tilt angles are 14°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent F(4) atoms. In the second Cu site, Cu(2) is bonded in a linear geometry to one O(3) and one O(6) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one W(2) and one Cu(1) atom. In the second O site, O(2) is bonded in a linear geometry to one W(1) and one Cu(1) atom. In the third O site, O(3) is bonded to two equivalent Mg(1), one W(1), and one Cu(2) atom to form distorted corner-sharing OMg2CuW trigonal pyramids. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Mg(1) and two equivalent W(1) atoms. In the fifth O site, O(5) is bonded in a linear geometry to two equivalent W(2) atoms. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(1), one W(2), and one Cu(2) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a distorted water-like geometry to one Mg(1) and one W(2) atom. In the second F site, F(2) is bonded in a distorted single-bond geometry to one W(1) atom. In the third F site, F(3) is bonded in a single-bond geometry to one W(1) atom. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one W(2) and two equivalent Cu(1) atoms.
MgW2Cu2(O3F2)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(4), one O(6), two equivalent O(3), and one F(1) atom to form distorted MgO4F trigonal bipyramids that share corners with two equivalent Mg(1)O4F trigonal bipyramids,  an edgeedge with one W(2)O4F2 octahedra, and edges with two equivalent W(1)O4F2 octahedra. The Mg(1)-O(4) bond length is 2.17 Å. The Mg(1)-O(6) bond length is 2.00 Å. Both Mg(1)-O(3) bond lengths are 2.10 Å. The Mg(1)-F(1) bond length is 1.95 Å. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(2), one O(3), two equivalent O(4), one F(2), and one F(3) atom to form WO4F2 octahedra that share corners with two equivalent W(1)O4F2 octahedra and edges with two equivalent Mg(1)O4F trigonal bipyramids. The corner-sharing octahedral tilt angles are 17°. The W(1)-O(2) bond length is 1.78 Å. The W(1)-O(3) bond length is 1.98 Å. Both W(1)-O(4) bond lengths are 1.96 Å. The W(1)-F(2) bond length is 2.04 Å. The W(1)-F(3) bond length is 1.93 Å. In the second W site, W(2) is bonded to one O(1), one O(6), two equivalent O(5), one F(1), and one F(4) atom to form WO4F2 octahedra that share corners with two equivalent W(2)O4F2 octahedra and  an edgeedge with one Mg(1)O4F trigonal bipyramid. The corner-sharing octahedral tilt angles are 14°. The W(2)-O(1) bond length is 1.78 Å. The W(2)-O(6) bond length is 1.90 Å. Both W(2)-O(5) bond lengths are 1.95 Å. The W(2)-F(1) bond length is 2.17 Å. The W(2)-F(4) bond length is 1.98 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent F(4) atoms. The Cu(1)-O(1) bond length is 1.83 Å. The Cu(1)-O(2) bond length is 1.82 Å. Both Cu(1)-F(4) bond lengths are 2.51 Å. In the second Cu site, Cu(2) is bonded in a linear geometry to one O(3) and one O(6) atom. The Cu(2)-O(3) bond length is 1.89 Å. The Cu(2)-O(6) bond length is 1.85 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one W(2) and one Cu(1) atom. In the second O site, O(2) is bonded in a linear geometry to one W(1) and one Cu(1) atom. In the third O site, O(3) is bonded to two equivalent Mg(1), one W(1), and one Cu(2) atom to form distorted corner-sharing OMg2CuW trigonal pyramids. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Mg(1) and two equivalent W(1) atoms. In the fifth O site, O(5) is bonded in a linear geometry to two equivalent W(2) atoms. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(1), one W(2), and one Cu(2) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a distorted water-like geometry to one Mg(1) and one W(2) atom. In the second F site, F(2) is bonded in a distorted single-bond geometry to one W(1) atom. In the third F site, F(3) is bonded in a single-bond geometry to one W(1) atom. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one W(2) and two equivalent Cu(1) atoms.