Ba3MgNb2ZnO9 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic Cm space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one Mg(1), one O(2), one O(5), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. In the second Ba site, Ba(2) is bonded to one O(4), one O(5), two equivalent O(2), two equivalent O(3), two equivalent O(6), and four equivalent O(1) atoms to form distorted BaO12 cuboctahedra that share corners with six equivalent Ba(2)O12 cuboctahedra,  an edgeedge with one Zn(1)O5 square pyramid, faces with two equivalent Nb(1)O6 octahedra, faces with three equivalent Nb(2)O6 octahedra, and faces with two equivalent Zn(1)O5 square pyramids. In the third Ba site, Ba(3) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms. Mg(1) is bonded in a rectangular see-saw-like geometry to one Ba(1), two equivalent O(3), and two equivalent O(6) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(4), one O(5), two equivalent O(3), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with three equivalent Nb(2)O6 octahedra, corners with two equivalent Zn(1)O5 square pyramids, and faces with two equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 7-8°. In the second Nb site, Nb(2) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with three equivalent Nb(1)O6 octahedra, corners with three equivalent Zn(1)O5 square pyramids, and faces with three equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 7-8°. Zn(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form distorted ZnO5 square pyramids that share corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra,  an edgeedge with one Ba(2)O12 cuboctahedra, and faces with two equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 7-17°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(3), two equivalent Ba(2), one Nb(2), and one Zn(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ba(1), two equivalent Ba(2), one Nb(2), and one Zn(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), one Mg(1), one Nb(1), and one Zn(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(1), and one Nb(1) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), two equivalent Ba(3), one Nb(1), and one Nb(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ba(2), one Ba(3), one Mg(1), one Nb(1), and one Nb(2) atom.
Ba3MgNb2ZnO9 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic Cm space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one Mg(1), one O(2), one O(5), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. The Ba(1)-Mg(1) bond length is 2.98 Å. The Ba(1)-O(2) bond length is 2.72 Å. The Ba(1)-O(5) bond length is 2.94 Å. Both Ba(1)-O(1) bond lengths are 2.71 Å. Both Ba(1)-O(3) bond lengths are 2.68 Å. Both Ba(1)-O(4) bond lengths are 3.18 Å. In the second Ba site, Ba(2) is bonded to one O(4), one O(5), two equivalent O(2), two equivalent O(3), two equivalent O(6), and four equivalent O(1) atoms to form distorted BaO12 cuboctahedra that share corners with six equivalent Ba(2)O12 cuboctahedra,  an edgeedge with one Zn(1)O5 square pyramid, faces with two equivalent Nb(1)O6 octahedra, faces with three equivalent Nb(2)O6 octahedra, and faces with two equivalent Zn(1)O5 square pyramids. The Ba(2)-O(4) bond length is 2.78 Å. The Ba(2)-O(5) bond length is 3.22 Å. Both Ba(2)-O(2) bond lengths are 2.95 Å. Both Ba(2)-O(3) bond lengths are 3.23 Å. Both Ba(2)-O(6) bond lengths are 3.06 Å. All Ba(2)-O(1) bond lengths are 3.13 Å. In the third Ba site, Ba(3) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms. The Ba(3)-O(4) bond length is 2.75 Å. Both Ba(3)-O(1) bond lengths are 2.74 Å. Both Ba(3)-O(5) bond lengths are 2.98 Å. Both Ba(3)-O(6) bond lengths are 2.78 Å. Mg(1) is bonded in a rectangular see-saw-like geometry to one Ba(1), two equivalent O(3), and two equivalent O(6) atoms. Both Mg(1)-O(3) bond lengths are 1.96 Å. Both Mg(1)-O(6) bond lengths are 2.03 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(4), one O(5), two equivalent O(3), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with three equivalent Nb(2)O6 octahedra, corners with two equivalent Zn(1)O5 square pyramids, and faces with two equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 7-8°. The Nb(1)-O(4) bond length is 1.97 Å. The Nb(1)-O(5) bond length is 2.26 Å. Both Nb(1)-O(3) bond lengths are 2.09 Å. Both Nb(1)-O(6) bond lengths are 2.11 Å. In the second Nb site, Nb(2) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with three equivalent Nb(1)O6 octahedra, corners with three equivalent Zn(1)O5 square pyramids, and faces with three equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 7-8°. The Nb(2)-O(2) bond length is 2.12 Å. The Nb(2)-O(5) bond length is 2.16 Å. Both Nb(2)-O(1) bond lengths are 2.04 Å. Both Nb(2)-O(6) bond lengths are 2.12 Å. Zn(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form distorted ZnO5 square pyramids that share corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra,  an edgeedge with one Ba(2)O12 cuboctahedra, and faces with two equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 7-17°. The Zn(1)-O(2) bond length is 2.08 Å. Both Zn(1)-O(1) bond lengths are 2.10 Å. Both Zn(1)-O(3) bond lengths are 2.15 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(3), two equivalent Ba(2), one Nb(2), and one Zn(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ba(1), two equivalent Ba(2), one Nb(2), and one Zn(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), one Mg(1), one Nb(1), and one Zn(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(1), and one Nb(1) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), two equivalent Ba(3), one Nb(1), and one Nb(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ba(2), one Ba(3), one Mg(1), one Nb(1), and one Nb(2) atom.