Mg2V2CuO8 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent V(1)O4 tetrahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. V(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form VO4 tetrahedra that share corners with three equivalent Cu(1)O6 octahedra and corners with six equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-61°. Cu(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form CuO6 octahedra that share corners with six equivalent V(1)O4 tetrahedra and edges with four equivalent Mg(1)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1), one V(1), and one Cu(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one V(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one V(1), and one Cu(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one V(1), and one Cu(1) atom.
Mg2V2CuO8 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent V(1)O4 tetrahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. The Mg(1)-O(3) bond length is 2.10 Å. The Mg(1)-O(4) bond length is 2.10 Å. There is one shorter (2.13 Å) and one longer (2.24 Å) Mg(1)-O(1) bond length. There is one shorter (2.03 Å) and one longer (2.07 Å) Mg(1)-O(2) bond length. V(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form VO4 tetrahedra that share corners with three equivalent Cu(1)O6 octahedra and corners with six equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-61°. The V(1)-O(1) bond length is 1.85 Å. The V(1)-O(2) bond length is 1.74 Å. The V(1)-O(3) bond length is 1.69 Å. The V(1)-O(4) bond length is 1.75 Å. Cu(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form CuO6 octahedra that share corners with six equivalent V(1)O4 tetrahedra and edges with four equivalent Mg(1)O6 octahedra. Both Cu(1)-O(1) bond lengths are 1.95 Å. Both Cu(1)-O(3) bond lengths are 2.40 Å. Both Cu(1)-O(4) bond lengths are 2.03 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1), one V(1), and one Cu(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one V(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one V(1), and one Cu(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one V(1), and one Cu(1) atom.