MgCuBi(WO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form MgO6 octahedra that share edges with two equivalent W(1)O6 octahedra and edges with two equivalent W(2)O6 octahedra. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form WO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra and edges with two equivalent W(2)O6 octahedra. In the second W site, W(2) is bonded to one O(1), one O(2), one O(4), one O(6), one O(7), and one O(8) atom to form WO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra and edges with two equivalent W(1)O6 octahedra. Cu(1) is bonded in a linear geometry to one O(2) and one O(7) atom. Bi(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one W(1), one W(2), and one Bi(1) atom. In the second O site, O(2) is bonded to one Mg(1), one W(1), one W(2), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing OMgCuW2 trigonal pyramids. In the third O site, O(3) is bonded in a distorted water-like geometry to one Mg(1), one W(1), and one Bi(1) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one Mg(1), one W(2), and one Bi(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mg(1), one W(1), and one Bi(1) atom. In the sixth O site, O(6) is bonded to one Mg(1), one W(1), one W(2), and one Bi(1) atom to form a mixture of distorted corner and edge-sharing OMgBiW2 trigonal pyramids. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one W(1), one W(2), and one Cu(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Mg(1), one W(2), and one Bi(1) atom.
MgCuBi(WO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form MgO6 octahedra that share edges with two equivalent W(1)O6 octahedra and edges with two equivalent W(2)O6 octahedra. The Mg(1)-O(2) bond length is 2.20 Å. The Mg(1)-O(3) bond length is 2.14 Å. The Mg(1)-O(4) bond length is 2.13 Å. The Mg(1)-O(5) bond length is 2.07 Å. The Mg(1)-O(6) bond length is 2.18 Å. The Mg(1)-O(8) bond length is 2.04 Å. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form WO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra and edges with two equivalent W(2)O6 octahedra. The W(1)-O(1) bond length is 2.06 Å. The W(1)-O(2) bond length is 2.18 Å. The W(1)-O(3) bond length is 1.82 Å. The W(1)-O(5) bond length is 2.04 Å. The W(1)-O(6) bond length is 2.09 Å. The W(1)-O(7) bond length is 2.05 Å. In the second W site, W(2) is bonded to one O(1), one O(2), one O(4), one O(6), one O(7), and one O(8) atom to form WO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra and edges with two equivalent W(1)O6 octahedra. The W(2)-O(1) bond length is 2.13 Å. The W(2)-O(2) bond length is 2.07 Å. The W(2)-O(4) bond length is 1.83 Å. The W(2)-O(6) bond length is 2.07 Å. The W(2)-O(7) bond length is 2.05 Å. The W(2)-O(8) bond length is 2.04 Å. Cu(1) is bonded in a linear geometry to one O(2) and one O(7) atom. The Cu(1)-O(2) bond length is 1.87 Å. The Cu(1)-O(7) bond length is 1.85 Å. Bi(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. The Bi(1)-O(1) bond length is 2.29 Å. The Bi(1)-O(3) bond length is 2.80 Å. The Bi(1)-O(4) bond length is 2.82 Å. The Bi(1)-O(5) bond length is 2.20 Å. The Bi(1)-O(6) bond length is 2.63 Å. The Bi(1)-O(8) bond length is 2.18 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one W(1), one W(2), and one Bi(1) atom. In the second O site, O(2) is bonded to one Mg(1), one W(1), one W(2), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing OMgCuW2 trigonal pyramids. In the third O site, O(3) is bonded in a distorted water-like geometry to one Mg(1), one W(1), and one Bi(1) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one Mg(1), one W(2), and one Bi(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mg(1), one W(1), and one Bi(1) atom. In the sixth O site, O(6) is bonded to one Mg(1), one W(1), one W(2), and one Bi(1) atom to form a mixture of distorted corner and edge-sharing OMgBiW2 trigonal pyramids. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one W(1), one W(2), and one Cu(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Mg(1), one W(2), and one Bi(1) atom.