MgCu6OF11 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one F(1), one F(11), one F(2), one F(3), and one F(5) atom to form MgOF5 octahedra that share  a cornercorner with one Cu(1)F5 square pyramid,  a cornercorner with one Cu(3)OF4 square pyramid, edges with two equivalent Cu(2)OF5 octahedra, edges with two equivalent Cu(4)OF5 octahedra,  an edgeedge with one Cu(1)F5 square pyramid, and  an edgeedge with one Cu(3)OF4 square pyramid. There are six inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one F(1), one F(10), one F(11), one F(3), and one F(9) atom to form CuF5 square pyramids that share  a cornercorner with one Mg(1)OF5 octahedra,  a cornercorner with one Cu(4)OF5 octahedra, corners with two equivalent Cu(5)F6 octahedra, corners with four equivalent Cu(2)OF5 octahedra, and  an edgeedge with one Mg(1)OF5 octahedra. The corner-sharing octahedral tilt angles range from 26-60°. In the second Cu site, Cu(2) is bonded to one O(1), one F(1), one F(11), one F(3), one F(8), and one F(9) atom to form CuOF5 octahedra that share  a cornercorner with one Cu(3)OF4 square pyramid, corners with four equivalent Cu(1)F5 square pyramids,  an edgeedge with one Cu(5)F6 octahedra,  an edgeedge with one Cu(4)OF5 octahedra, and edges with two equivalent Mg(1)OF5 octahedra. In the third Cu site, Cu(3) is bonded to one O(1), one F(2), one F(4), one F(5), and one F(6) atom to form distorted CuOF4 square pyramids that share  a cornercorner with one Mg(1)OF5 octahedra,  a cornercorner with one Cu(2)OF5 octahedra, corners with two equivalent Cu(5)F6 octahedra, corners with four equivalent Cu(4)OF5 octahedra, and  an edgeedge with one Mg(1)OF5 octahedra. The corner-sharing octahedral tilt angles range from 28-65°. In the fourth Cu site, Cu(4) is bonded to one O(1), one F(2), one F(3), one F(4), one F(5), and one F(7) atom to form distorted CuOF5 octahedra that share  a cornercorner with one Cu(1)F5 square pyramid, corners with four equivalent Cu(3)OF4 square pyramids,  an edgeedge with one Cu(5)F6 octahedra,  an edgeedge with one Cu(2)OF5 octahedra, and edges with two equivalent Mg(1)OF5 octahedra. In the fifth Cu site, Cu(5) is bonded to one F(10), one F(4), one F(6), one F(7), one F(8), and one F(9) atom to form CuF6 octahedra that share corners with two equivalent Cu(1)F5 square pyramids, corners with two equivalent Cu(3)OF4 square pyramids,  an edgeedge with one Cu(2)OF5 octahedra, and  an edgeedge with one Cu(4)OF5 octahedra. In the sixth Cu site, Cu(6) is bonded in a distorted rectangular see-saw-like geometry to one F(10), one F(11), one F(5), one F(6), one F(7), and one F(8) atom. O(1) is bonded in a trigonal pyramidal geometry to one Mg(1), one Cu(2), one Cu(3), and one Cu(4) atom. There are eleven inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cu(1), and one Cu(2) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cu(3), and one Cu(4) atom. In the third F site, F(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Cu(1), one Cu(2), and one Cu(4) atom. In the fourth F site, F(4) is bonded in a trigonal planar geometry to one Cu(3), one Cu(4), and one Cu(5) atom. In the fifth F site, F(5) is bonded in a 4-coordinate geometry to one Mg(1), one Cu(3), one Cu(4), and one Cu(6) atom. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Cu(3), one Cu(5), and one Cu(6) atom. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to one Cu(4), one Cu(5), and one Cu(6) atom. In the eighth F site, F(8) is bonded in a distorted trigonal planar geometry to one Cu(2), one Cu(5), and one Cu(6) atom. In the ninth F site, F(9) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one Cu(5) atom. In the tenth F site, F(10) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(5), and one Cu(6) atom. In the eleventh F site, F(11) is bonded in a 4-coordinate geometry to one Mg(1), one Cu(1), one Cu(2), and one Cu(6) atom.
MgCu6OF11 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one F(1), one F(11), one F(2), one F(3), and one F(5) atom to form MgOF5 octahedra that share  a cornercorner with one Cu(1)F5 square pyramid,  a cornercorner with one Cu(3)OF4 square pyramid, edges with two equivalent Cu(2)OF5 octahedra, edges with two equivalent Cu(4)OF5 octahedra,  an edgeedge with one Cu(1)F5 square pyramid, and  an edgeedge with one Cu(3)OF4 square pyramid. The Mg(1)-O(1) bond length is 2.00 Å. The Mg(1)-F(1) bond length is 2.03 Å. The Mg(1)-F(11) bond length is 2.00 Å. The Mg(1)-F(2) bond length is 2.01 Å. The Mg(1)-F(3) bond length is 1.98 Å. The Mg(1)-F(5) bond length is 2.00 Å. There are six inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one F(1), one F(10), one F(11), one F(3), and one F(9) atom to form CuF5 square pyramids that share  a cornercorner with one Mg(1)OF5 octahedra,  a cornercorner with one Cu(4)OF5 octahedra, corners with two equivalent Cu(5)F6 octahedra, corners with four equivalent Cu(2)OF5 octahedra, and  an edgeedge with one Mg(1)OF5 octahedra. The corner-sharing octahedral tilt angles range from 26-60°. The Cu(1)-F(1) bond length is 2.00 Å. The Cu(1)-F(10) bond length is 2.11 Å. The Cu(1)-F(11) bond length is 2.11 Å. The Cu(1)-F(3) bond length is 1.99 Å. The Cu(1)-F(9) bond length is 1.92 Å. In the second Cu site, Cu(2) is bonded to one O(1), one F(1), one F(11), one F(3), one F(8), and one F(9) atom to form CuOF5 octahedra that share  a cornercorner with one Cu(3)OF4 square pyramid, corners with four equivalent Cu(1)F5 square pyramids,  an edgeedge with one Cu(5)F6 octahedra,  an edgeedge with one Cu(4)OF5 octahedra, and edges with two equivalent Mg(1)OF5 octahedra. The Cu(2)-O(1) bond length is 1.98 Å. The Cu(2)-F(1) bond length is 2.13 Å. The Cu(2)-F(11) bond length is 2.19 Å. The Cu(2)-F(3) bond length is 2.15 Å. The Cu(2)-F(8) bond length is 2.21 Å. The Cu(2)-F(9) bond length is 2.01 Å. In the third Cu site, Cu(3) is bonded to one O(1), one F(2), one F(4), one F(5), and one F(6) atom to form distorted CuOF4 square pyramids that share  a cornercorner with one Mg(1)OF5 octahedra,  a cornercorner with one Cu(2)OF5 octahedra, corners with two equivalent Cu(5)F6 octahedra, corners with four equivalent Cu(4)OF5 octahedra, and  an edgeedge with one Mg(1)OF5 octahedra. The corner-sharing octahedral tilt angles range from 28-65°. The Cu(3)-O(1) bond length is 1.95 Å. The Cu(3)-F(2) bond length is 2.00 Å. The Cu(3)-F(4) bond length is 2.09 Å. The Cu(3)-F(5) bond length is 2.24 Å. The Cu(3)-F(6) bond length is 2.09 Å. In the fourth Cu site, Cu(4) is bonded to one O(1), one F(2), one F(3), one F(4), one F(5), and one F(7) atom to form distorted CuOF5 octahedra that share  a cornercorner with one Cu(1)F5 square pyramid, corners with four equivalent Cu(3)OF4 square pyramids,  an edgeedge with one Cu(5)F6 octahedra,  an edgeedge with one Cu(2)OF5 octahedra, and edges with two equivalent Mg(1)OF5 octahedra. The Cu(4)-O(1) bond length is 1.93 Å. The Cu(4)-F(2) bond length is 2.11 Å. The Cu(4)-F(3) bond length is 2.41 Å. The Cu(4)-F(4) bond length is 2.10 Å. The Cu(4)-F(5) bond length is 2.03 Å. The Cu(4)-F(7) bond length is 2.16 Å. In the fifth Cu site, Cu(5) is bonded to one F(10), one F(4), one F(6), one F(7), one F(8), and one F(9) atom to form CuF6 octahedra that share corners with two equivalent Cu(1)F5 square pyramids, corners with two equivalent Cu(3)OF4 square pyramids,  an edgeedge with one Cu(2)OF5 octahedra, and  an edgeedge with one Cu(4)OF5 octahedra. The Cu(5)-F(10) bond length is 2.20 Å. The Cu(5)-F(4) bond length is 2.06 Å. The Cu(5)-F(6) bond length is 2.27 Å. The Cu(5)-F(7) bond length is 1.96 Å. The Cu(5)-F(8) bond length is 1.99 Å. The Cu(5)-F(9) bond length is 2.05 Å. In the sixth Cu site, Cu(6) is bonded in a distorted rectangular see-saw-like geometry to one F(10), one F(11), one F(5), one F(6), one F(7), and one F(8) atom. The Cu(6)-F(10) bond length is 1.92 Å. The Cu(6)-F(11) bond length is 2.53 Å. The Cu(6)-F(5) bond length is 2.58 Å. The Cu(6)-F(6) bond length is 1.92 Å. The Cu(6)-F(7) bond length is 1.94 Å. The Cu(6)-F(8) bond length is 1.95 Å. O(1) is bonded in a trigonal pyramidal geometry to one Mg(1), one Cu(2), one Cu(3), and one Cu(4) atom. There are eleven inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cu(1), and one Cu(2) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cu(3), and one Cu(4) atom. In the third F site, F(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Cu(1), one Cu(2), and one Cu(4) atom. In the fourth F site, F(4) is bonded in a trigonal planar geometry to one Cu(3), one Cu(4), and one Cu(5) atom. In the fifth F site, F(5) is bonded in a 4-coordinate geometry to one Mg(1), one Cu(3), one Cu(4), and one Cu(6) atom. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Cu(3), one Cu(5), and one Cu(6) atom. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to one Cu(4), one Cu(5), and one Cu(6) atom. In the eighth F site, F(8) is bonded in a distorted trigonal planar geometry to one Cu(2), one Cu(5), and one Cu(6) atom. In the ninth F site, F(9) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one Cu(5) atom. In the tenth F site, F(10) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(5), and one Cu(6) atom. In the eleventh F site, F(11) is bonded in a 4-coordinate geometry to one Mg(1), one Cu(1), one Cu(2), and one Cu(6) atom.