BaMgV2CuO8 crystallizes in the orthorhombic Iba2 space group. Ba(1) is bonded to one O(1), one O(2), one O(3), one O(4), two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms to form BaO12 cuboctahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  a cornercorner with one V(1)O4 tetrahedra,  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(3)O4 tetrahedra,  an edgeedge with one V(1)O4 tetrahedra,  an edgeedge with one V(2)O4 tetrahedra, edges with two equivalent V(3)O4 tetrahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Mg(1)O6 octahedra, and faces with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-53°. Mg(1) is bonded to one O(1), one O(2), one O(5), one O(8), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(1)O4 tetrahedra, corners with three equivalent V(3)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and faces with two equivalent Ba(1)O12 cuboctahedra. There are three inequivalent V sites. In the first V site, V(1) is bonded to two equivalent O(1) and two equivalent O(5) atoms to form VO4 tetrahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Cu(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, and edges with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 44-57°. In the second V site, V(2) is bonded to two equivalent O(2) and two equivalent O(6) atoms to form VO4 tetrahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra, and edges with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the third V site, V(3) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form VO4 tetrahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Cu(1)O6 octahedra, and edges with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 44-58°. Cu(1) is bonded to one O(1), one O(2), one O(6), one O(7), and two equivalent O(3) atoms to form CuO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one V(1)O4 tetrahedra, corners with two equivalent V(2)O4 tetrahedra, corners with three equivalent V(3)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and faces with two equivalent Ba(1)O12 cuboctahedra. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one V(3), and one Cu(1) atom. In the second O site, O(8) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Mg(1), and one V(3) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Ba(1), one Mg(1), one V(1), and one Cu(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), one Mg(1), one V(2), and one Cu(1) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one V(3), and two equivalent Cu(1) atoms. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one Ba(1), two equivalent Mg(1), and one V(3) atom. In the seventh O site, O(5) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Mg(1), and one V(1) atom. In the eighth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one V(2), and one Cu(1) atom.
BaMgV2CuO8 crystallizes in the orthorhombic Iba2 space group. Ba(1) is bonded to one O(1), one O(2), one O(3), one O(4), two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms to form BaO12 cuboctahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  a cornercorner with one V(1)O4 tetrahedra,  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(3)O4 tetrahedra,  an edgeedge with one V(1)O4 tetrahedra,  an edgeedge with one V(2)O4 tetrahedra, edges with two equivalent V(3)O4 tetrahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Mg(1)O6 octahedra, and faces with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-53°. The Ba(1)-O(1) bond length is 3.03 Å. The Ba(1)-O(2) bond length is 3.02 Å. The Ba(1)-O(3) bond length is 2.99 Å. The Ba(1)-O(4) bond length is 3.05 Å. There is one shorter (2.79 Å) and one longer (3.14 Å) Ba(1)-O(5) bond length. There is one shorter (2.79 Å) and one longer (3.11 Å) Ba(1)-O(6) bond length. There is one shorter (2.76 Å) and one longer (3.09 Å) Ba(1)-O(7) bond length. There is one shorter (2.78 Å) and one longer (3.11 Å) Ba(1)-O(8) bond length. Mg(1) is bonded to one O(1), one O(2), one O(5), one O(8), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(1)O4 tetrahedra, corners with three equivalent V(3)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and faces with two equivalent Ba(1)O12 cuboctahedra. The Mg(1)-O(1) bond length is 2.18 Å. The Mg(1)-O(2) bond length is 2.03 Å. The Mg(1)-O(5) bond length is 2.13 Å. The Mg(1)-O(8) bond length is 2.12 Å. There is one shorter (2.05 Å) and one longer (2.21 Å) Mg(1)-O(4) bond length. There are three inequivalent V sites. In the first V site, V(1) is bonded to two equivalent O(1) and two equivalent O(5) atoms to form VO4 tetrahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Cu(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, and edges with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 44-57°. Both V(1)-O(1) bond lengths are 1.79 Å. Both V(1)-O(5) bond lengths are 1.72 Å. In the second V site, V(2) is bonded to two equivalent O(2) and two equivalent O(6) atoms to form VO4 tetrahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra, and edges with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 45-55°. Both V(2)-O(2) bond lengths are 1.76 Å. Both V(2)-O(6) bond lengths are 1.74 Å. In the third V site, V(3) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form VO4 tetrahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Cu(1)O6 octahedra, and edges with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 44-58°. The V(3)-O(3) bond length is 1.78 Å. The V(3)-O(4) bond length is 1.77 Å. The V(3)-O(7) bond length is 1.73 Å. The V(3)-O(8) bond length is 1.73 Å. Cu(1) is bonded to one O(1), one O(2), one O(6), one O(7), and two equivalent O(3) atoms to form CuO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one V(1)O4 tetrahedra, corners with two equivalent V(2)O4 tetrahedra, corners with three equivalent V(3)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and faces with two equivalent Ba(1)O12 cuboctahedra. The Cu(1)-O(1) bond length is 2.00 Å. The Cu(1)-O(2) bond length is 2.22 Å. The Cu(1)-O(6) bond length is 2.09 Å. The Cu(1)-O(7) bond length is 2.16 Å. There is one shorter (1.97 Å) and one longer (2.28 Å) Cu(1)-O(3) bond length. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one V(3), and one Cu(1) atom. In the second O site, O(8) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Mg(1), and one V(3) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Ba(1), one Mg(1), one V(1), and one Cu(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), one Mg(1), one V(2), and one Cu(1) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one V(3), and two equivalent Cu(1) atoms. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one Ba(1), two equivalent Mg(1), and one V(3) atom. In the seventh O site, O(5) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Mg(1), and one V(1) atom. In the eighth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one V(2), and one Cu(1) atom.