Mg2CuSbO6 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(2), and four equivalent O(1) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), and four equivalent O(2) atoms. Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted CuO6 octahedra that share corners with two equivalent Cu(1)O6 octahedra and corners with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-52°. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra and corners with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-53°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Mg(1), one Cu(1), and one Sb(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(2), one Cu(1), and one Sb(1) atom. In the third O site, O(3) is bonded to one Mg(1), one Mg(2), and two equivalent Sb(1) atoms to form OMg2Sb2 tetrahedra that share corners with two equivalent O(3)Mg2Sb2 tetrahedra and corners with two equivalent O(4)Mg2Cu2 trigonal pyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Mg(2), and two equivalent Cu(1) atoms to form distorted OMg2Cu2 trigonal pyramids that share corners with two equivalent O(3)Mg2Sb2 tetrahedra and corners with two equivalent O(4)Mg2Cu2 trigonal pyramids.
Mg2CuSbO6 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(2), and four equivalent O(1) atoms. The Mg(1)-O(3) bond length is 2.24 Å. The Mg(1)-O(4) bond length is 2.13 Å. Both Mg(1)-O(2) bond lengths are 2.34 Å. There are two shorter (2.17 Å) and two longer (2.55 Å) Mg(1)-O(1) bond lengths. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), and four equivalent O(2) atoms. The Mg(2)-O(3) bond length is 2.08 Å. The Mg(2)-O(4) bond length is 2.04 Å. There are two shorter (2.01 Å) and two longer (2.58 Å) Mg(2)-O(2) bond lengths. Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted CuO6 octahedra that share corners with two equivalent Cu(1)O6 octahedra and corners with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-52°. Both Cu(1)-O(1) bond lengths are 1.86 Å. Both Cu(1)-O(2) bond lengths are 2.53 Å. Both Cu(1)-O(4) bond lengths are 1.95 Å. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra and corners with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-53°. Both Sb(1)-O(1) bond lengths are 2.02 Å. Both Sb(1)-O(2) bond lengths are 1.96 Å. Both Sb(1)-O(3) bond lengths are 2.06 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Mg(1), one Cu(1), and one Sb(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(2), one Cu(1), and one Sb(1) atom. In the third O site, O(3) is bonded to one Mg(1), one Mg(2), and two equivalent Sb(1) atoms to form OMg2Sb2 tetrahedra that share corners with two equivalent O(3)Mg2Sb2 tetrahedra and corners with two equivalent O(4)Mg2Cu2 trigonal pyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Mg(2), and two equivalent Cu(1) atoms to form distorted OMg2Cu2 trigonal pyramids that share corners with two equivalent O(3)Mg2Sb2 tetrahedra and corners with two equivalent O(4)Mg2Cu2 trigonal pyramids.