MgGa4(CuO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form distorted MgO6 octahedra that share corners with six equivalent Ga(4)O6 octahedra, edges with two equivalent Ga(1)O6 octahedra, edges with two equivalent Ga(2)O6 octahedra, and edges with two equivalent Ga(3)O6 octahedra. The corner-sharing octahedral tilt angles are 8°. 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), one O(7), and one O(8) atom. In the second Cu site, Cu(2) is bonded in a distorted rectangular see-saw-like geometry to one O(3), one O(4), one O(5), and one O(6) atom. There are four inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form GaO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ga(2)O6 octahedra, edges with two equivalent Ga(3)O6 octahedra, and edges with two equivalent Ga(4)O6 octahedra. In the second Ga site, Ga(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form GaO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ga(1)O6 octahedra, edges with two equivalent Ga(3)O6 octahedra, and edges with two equivalent Ga(4)O6 octahedra. In the third Ga site, Ga(3) is bonded to one O(1), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form GaO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ga(1)O6 octahedra, edges with two equivalent Ga(2)O6 octahedra, and edges with two equivalent Ga(4)O6 octahedra. In the fourth Ga site, Ga(4) is bonded to one O(2), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form GaO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, edges with two equivalent Ga(1)O6 octahedra, edges with two equivalent Ga(2)O6 octahedra, and edges with two equivalent Ga(3)O6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Cu(1), one Ga(1), one Ga(2), and one Ga(3) atom to form OGa3Cu tetrahedra that share  a cornercorner with one O(2)MgGa3Cu square pyramid,  a cornercorner with one O(7)MgGa3Cu square pyramid,  a cornercorner with one O(8)MgGa3Cu square pyramid, corners with two equivalent O(3)MgGa3Cu square pyramids, corners with two equivalent O(5)MgGa3Cu square pyramids, corners with two equivalent O(6)MgGa3Cu square pyramids, corners with three equivalent O(4)Ga3Cu tetrahedra,  an edgeedge with one O(2)MgGa3Cu square pyramid,  an edgeedge with one O(7)MgGa3Cu square pyramid, and  an edgeedge with one O(8)MgGa3Cu square pyramid. In the second O site, O(2) is bonded to one Mg(1), one Cu(1), one Ga(1), one Ga(2), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(5)MgGa3Cu square pyramid,  a cornercorner with one O(6)MgGa3Cu square pyramid, corners with four equivalent O(3)MgGa3Cu square pyramids,  a cornercorner with one O(1)Ga3Cu tetrahedra, corners with two equivalent O(4)Ga3Cu tetrahedra,  an edgeedge with one O(5)MgGa3Cu square pyramid,  an edgeedge with one O(6)MgGa3Cu square pyramid, edges with two equivalent O(7)MgGa3Cu square pyramids, edges with two equivalent O(8)MgGa3Cu square pyramids, and  an edgeedge with one O(1)Ga3Cu tetrahedra. In the third O site, O(3) is bonded to one Mg(1), one Cu(2), one Ga(1), one Ga(2), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(7)MgGa3Cu square pyramid,  a cornercorner with one O(8)MgGa3Cu square pyramid, corners with four equivalent O(2)MgGa3Cu square pyramids,  a cornercorner with one O(4)Ga3Cu tetrahedra, corners with two equivalent O(1)Ga3Cu tetrahedra,  an edgeedge with one O(7)MgGa3Cu square pyramid,  an edgeedge with one O(8)MgGa3Cu square pyramid, edges with two equivalent O(5)MgGa3Cu square pyramids, edges with two equivalent O(6)MgGa3Cu square pyramids, and  an edgeedge with one O(4)Ga3Cu tetrahedra. In the fourth O site, O(4) is bonded to one Cu(2), one Ga(1), one Ga(2), and one Ga(3) atom to form OGa3Cu tetrahedra that share  a cornercorner with one O(3)MgGa3Cu square pyramid,  a cornercorner with one O(5)MgGa3Cu square pyramid,  a cornercorner with one O(6)MgGa3Cu square pyramid, corners with two equivalent O(2)MgGa3Cu square pyramids, corners with two equivalent O(7)MgGa3Cu square pyramids, corners with two equivalent O(8)MgGa3Cu square pyramids, corners with three equivalent O(1)Ga3Cu tetrahedra,  an edgeedge with one O(3)MgGa3Cu square pyramid,  an edgeedge with one O(5)MgGa3Cu square pyramid, and  an edgeedge with one O(6)MgGa3Cu square pyramid. In the fifth O site, O(5) is bonded to one Mg(1), one Cu(2), one Ga(1), one Ga(3), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(2)MgGa3Cu square pyramid,  a cornercorner with one O(8)MgGa3Cu square pyramid, corners with four equivalent O(7)MgGa3Cu square pyramids,  a cornercorner with one O(4)Ga3Cu tetrahedra, corners with two equivalent O(1)Ga3Cu tetrahedra,  an edgeedge with one O(2)MgGa3Cu square pyramid,  an edgeedge with one O(8)MgGa3Cu square pyramid, edges with two equivalent O(3)MgGa3Cu square pyramids, edges with two equivalent O(6)MgGa3Cu square pyramids, and  an edgeedge with one O(4)Ga3Cu tetrahedra. In the sixth O site, O(6) is bonded to one Mg(1), one Cu(2), one Ga(2), one Ga(3), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(2)MgGa3Cu square pyramid,  a cornercorner with one O(7)MgGa3Cu square pyramid, corners with four equivalent O(8)MgGa3Cu square pyramids,  a cornercorner with one O(4)Ga3Cu tetrahedra, corners with two equivalent O(1)Ga3Cu tetrahedra,  an edgeedge with one O(2)MgGa3Cu square pyramid,  an edgeedge with one O(7)MgGa3Cu square pyramid, edges with two equivalent O(3)MgGa3Cu square pyramids, edges with two equivalent O(5)MgGa3Cu square pyramids, and  an edgeedge with one O(4)Ga3Cu tetrahedra. In the seventh O site, O(7) is bonded to one Mg(1), one Cu(1), one Ga(1), one Ga(3), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(3)MgGa3Cu square pyramid,  a cornercorner with one O(6)MgGa3Cu square pyramid, corners with four equivalent O(5)MgGa3Cu square pyramids,  a cornercorner with one O(1)Ga3Cu tetrahedra, corners with two equivalent O(4)Ga3Cu tetrahedra,  an edgeedge with one O(3)MgGa3Cu square pyramid,  an edgeedge with one O(6)MgGa3Cu square pyramid, edges with two equivalent O(2)MgGa3Cu square pyramids, edges with two equivalent O(8)MgGa3Cu square pyramids, and  an edgeedge with one O(1)Ga3Cu tetrahedra. In the eighth O site, O(8) is bonded to one Mg(1), one Cu(1), one Ga(2), one Ga(3), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(3)MgGa3Cu square pyramid,  a cornercorner with one O(5)MgGa3Cu square pyramid, corners with four equivalent O(6)MgGa3Cu square pyramids,  a cornercorner with one O(1)Ga3Cu tetrahedra, corners with two equivalent O(4)Ga3Cu tetrahedra,  an edgeedge with one O(3)MgGa3Cu square pyramid,  an edgeedge with one O(5)MgGa3Cu square pyramid, edges with two equivalent O(2)MgGa3Cu square pyramids, edges with two equivalent O(7)MgGa3Cu square pyramids, and  an edgeedge with one O(1)Ga3Cu tetrahedra.
MgGa4(CuO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form distorted MgO6 octahedra that share corners with six equivalent Ga(4)O6 octahedra, edges with two equivalent Ga(1)O6 octahedra, edges with two equivalent Ga(2)O6 octahedra, and edges with two equivalent Ga(3)O6 octahedra. The corner-sharing octahedral tilt angles are 8°. The Mg(1)-O(2) bond length is 2.19 Å. The Mg(1)-O(3) bond length is 2.18 Å. The Mg(1)-O(5) bond length is 2.19 Å. The Mg(1)-O(6) bond length is 2.19 Å. The Mg(1)-O(7) bond length is 2.18 Å. The Mg(1)-O(8) bond length is 2.19 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), one O(7), and one O(8) atom. The Cu(1)-O(1) bond length is 1.87 Å. The Cu(1)-O(2) bond length is 2.17 Å. The Cu(1)-O(7) bond length is 2.23 Å. The Cu(1)-O(8) bond length is 2.19 Å. In the second Cu site, Cu(2) is bonded in a distorted rectangular see-saw-like geometry to one O(3), one O(4), one O(5), and one O(6) atom. The Cu(2)-O(3) bond length is 2.22 Å. The Cu(2)-O(4) bond length is 1.87 Å. The Cu(2)-O(5) bond length is 2.18 Å. The Cu(2)-O(6) bond length is 2.19 Å. There are four inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form GaO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ga(2)O6 octahedra, edges with two equivalent Ga(3)O6 octahedra, and edges with two equivalent Ga(4)O6 octahedra. The Ga(1)-O(1) bond length is 1.95 Å. The Ga(1)-O(2) bond length is 2.05 Å. The Ga(1)-O(3) bond length is 2.06 Å. The Ga(1)-O(4) bond length is 1.95 Å. The Ga(1)-O(5) bond length is 2.05 Å. The Ga(1)-O(7) bond length is 2.06 Å. In the second Ga site, Ga(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form GaO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ga(1)O6 octahedra, edges with two equivalent Ga(3)O6 octahedra, and edges with two equivalent Ga(4)O6 octahedra. The Ga(2)-O(1) bond length is 1.95 Å. The Ga(2)-O(2) bond length is 2.06 Å. The Ga(2)-O(3) bond length is 2.06 Å. The Ga(2)-O(4) bond length is 1.95 Å. The Ga(2)-O(6) bond length is 2.05 Å. The Ga(2)-O(8) bond length is 2.06 Å. In the third Ga site, Ga(3) is bonded to one O(1), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form GaO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ga(1)O6 octahedra, edges with two equivalent Ga(2)O6 octahedra, and edges with two equivalent Ga(4)O6 octahedra. The Ga(3)-O(1) bond length is 1.95 Å. The Ga(3)-O(4) bond length is 1.95 Å. The Ga(3)-O(5) bond length is 2.06 Å. The Ga(3)-O(6) bond length is 2.06 Å. The Ga(3)-O(7) bond length is 2.05 Å. The Ga(3)-O(8) bond length is 2.05 Å. In the fourth Ga site, Ga(4) is bonded to one O(2), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form GaO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, edges with two equivalent Ga(1)O6 octahedra, edges with two equivalent Ga(2)O6 octahedra, and edges with two equivalent Ga(3)O6 octahedra. The corner-sharing octahedral tilt angles are 8°. The Ga(4)-O(2) bond length is 2.14 Å. The Ga(4)-O(3) bond length is 2.13 Å. The Ga(4)-O(5) bond length is 2.14 Å. The Ga(4)-O(6) bond length is 2.14 Å. The Ga(4)-O(7) bond length is 2.13 Å. The Ga(4)-O(8) bond length is 2.14 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Cu(1), one Ga(1), one Ga(2), and one Ga(3) atom to form OGa3Cu tetrahedra that share  a cornercorner with one O(2)MgGa3Cu square pyramid,  a cornercorner with one O(7)MgGa3Cu square pyramid,  a cornercorner with one O(8)MgGa3Cu square pyramid, corners with two equivalent O(3)MgGa3Cu square pyramids, corners with two equivalent O(5)MgGa3Cu square pyramids, corners with two equivalent O(6)MgGa3Cu square pyramids, corners with three equivalent O(4)Ga3Cu tetrahedra,  an edgeedge with one O(2)MgGa3Cu square pyramid,  an edgeedge with one O(7)MgGa3Cu square pyramid, and  an edgeedge with one O(8)MgGa3Cu square pyramid. In the second O site, O(2) is bonded to one Mg(1), one Cu(1), one Ga(1), one Ga(2), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(5)MgGa3Cu square pyramid,  a cornercorner with one O(6)MgGa3Cu square pyramid, corners with four equivalent O(3)MgGa3Cu square pyramids,  a cornercorner with one O(1)Ga3Cu tetrahedra, corners with two equivalent O(4)Ga3Cu tetrahedra,  an edgeedge with one O(5)MgGa3Cu square pyramid,  an edgeedge with one O(6)MgGa3Cu square pyramid, edges with two equivalent O(7)MgGa3Cu square pyramids, edges with two equivalent O(8)MgGa3Cu square pyramids, and  an edgeedge with one O(1)Ga3Cu tetrahedra. In the third O site, O(3) is bonded to one Mg(1), one Cu(2), one Ga(1), one Ga(2), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(7)MgGa3Cu square pyramid,  a cornercorner with one O(8)MgGa3Cu square pyramid, corners with four equivalent O(2)MgGa3Cu square pyramids,  a cornercorner with one O(4)Ga3Cu tetrahedra, corners with two equivalent O(1)Ga3Cu tetrahedra,  an edgeedge with one O(7)MgGa3Cu square pyramid,  an edgeedge with one O(8)MgGa3Cu square pyramid, edges with two equivalent O(5)MgGa3Cu square pyramids, edges with two equivalent O(6)MgGa3Cu square pyramids, and  an edgeedge with one O(4)Ga3Cu tetrahedra. In the fourth O site, O(4) is bonded to one Cu(2), one Ga(1), one Ga(2), and one Ga(3) atom to form OGa3Cu tetrahedra that share  a cornercorner with one O(3)MgGa3Cu square pyramid,  a cornercorner with one O(5)MgGa3Cu square pyramid,  a cornercorner with one O(6)MgGa3Cu square pyramid, corners with two equivalent O(2)MgGa3Cu square pyramids, corners with two equivalent O(7)MgGa3Cu square pyramids, corners with two equivalent O(8)MgGa3Cu square pyramids, corners with three equivalent O(1)Ga3Cu tetrahedra,  an edgeedge with one O(3)MgGa3Cu square pyramid,  an edgeedge with one O(5)MgGa3Cu square pyramid, and  an edgeedge with one O(6)MgGa3Cu square pyramid. In the fifth O site, O(5) is bonded to one Mg(1), one Cu(2), one Ga(1), one Ga(3), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(2)MgGa3Cu square pyramid,  a cornercorner with one O(8)MgGa3Cu square pyramid, corners with four equivalent O(7)MgGa3Cu square pyramids,  a cornercorner with one O(4)Ga3Cu tetrahedra, corners with two equivalent O(1)Ga3Cu tetrahedra,  an edgeedge with one O(2)MgGa3Cu square pyramid,  an edgeedge with one O(8)MgGa3Cu square pyramid, edges with two equivalent O(3)MgGa3Cu square pyramids, edges with two equivalent O(6)MgGa3Cu square pyramids, and  an edgeedge with one O(4)Ga3Cu tetrahedra. In the sixth O site, O(6) is bonded to one Mg(1), one Cu(2), one Ga(2), one Ga(3), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(2)MgGa3Cu square pyramid,  a cornercorner with one O(7)MgGa3Cu square pyramid, corners with four equivalent O(8)MgGa3Cu square pyramids,  a cornercorner with one O(4)Ga3Cu tetrahedra, corners with two equivalent O(1)Ga3Cu tetrahedra,  an edgeedge with one O(2)MgGa3Cu square pyramid,  an edgeedge with one O(7)MgGa3Cu square pyramid, edges with two equivalent O(3)MgGa3Cu square pyramids, edges with two equivalent O(5)MgGa3Cu square pyramids, and  an edgeedge with one O(4)Ga3Cu tetrahedra. In the seventh O site, O(7) is bonded to one Mg(1), one Cu(1), one Ga(1), one Ga(3), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(3)MgGa3Cu square pyramid,  a cornercorner with one O(6)MgGa3Cu square pyramid, corners with four equivalent O(5)MgGa3Cu square pyramids,  a cornercorner with one O(1)Ga3Cu tetrahedra, corners with two equivalent O(4)Ga3Cu tetrahedra,  an edgeedge with one O(3)MgGa3Cu square pyramid,  an edgeedge with one O(6)MgGa3Cu square pyramid, edges with two equivalent O(2)MgGa3Cu square pyramids, edges with two equivalent O(8)MgGa3Cu square pyramids, and  an edgeedge with one O(1)Ga3Cu tetrahedra. In the eighth O site, O(8) is bonded to one Mg(1), one Cu(1), one Ga(2), one Ga(3), and one Ga(4) atom to form OMgGa3Cu square pyramids that share  a cornercorner with one O(3)MgGa3Cu square pyramid,  a cornercorner with one O(5)MgGa3Cu square pyramid, corners with four equivalent O(6)MgGa3Cu square pyramids,  a cornercorner with one O(1)Ga3Cu tetrahedra, corners with two equivalent O(4)Ga3Cu tetrahedra,  an edgeedge with one O(3)MgGa3Cu square pyramid,  an edgeedge with one O(5)MgGa3Cu square pyramid, edges with two equivalent O(2)MgGa3Cu square pyramids, edges with two equivalent O(7)MgGa3Cu square pyramids, and  an edgeedge with one O(1)Ga3Cu tetrahedra.