Mg8V5O16 crystallizes in the triclinic P1 space group. There are eight inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), one O(14), one O(2), and one O(5) atom to form MgO4 tetrahedra that share  a cornercorner with one Mg(3)O6 octahedra,  a cornercorner with one V(4)O6 octahedra,  a cornercorner with one V(5)O6 octahedra, corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and corners with three equivalent V(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-63°. In the second Mg site, Mg(2) is bonded to one O(10), one O(12), one O(13), one O(4), one O(6), and one O(7) atom to form MgO6 octahedra that share  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one V(1)O6 octahedra,  an edgeedge with one V(2)O6 octahedra,  an edgeedge with one V(4)O6 octahedra,  an edgeedge with one V(5)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, edges with two equivalent Mg(6)O6 octahedra, and edges with two equivalent Mg(7)O6 octahedra. In the third Mg site, Mg(3) is bonded to one O(11), one O(14), one O(15), one O(6), one O(7), and one O(9) atom to form MgO6 octahedra that share corners with three equivalent Mg(5)O6 octahedra,  a cornercorner with one Mg(1)O4 tetrahedra, corners with two equivalent Mg(8)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one Mg(7)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent V(4)O6 octahedra, and edges with two equivalent V(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-9°. In the fourth Mg site, Mg(4) is bonded to one O(10), one O(12), one O(2), one O(3), one O(5), and one O(8) atom to form MgO6 octahedra that share corners with three equivalent Mg(5)O6 octahedra,  a cornercorner with one Mg(8)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one Mg(7)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent V(1)O6 octahedra, and edges with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-6°. In the fifth Mg site, Mg(5) is bonded to one O(10), one O(12), one O(6), one O(7), one O(8), and one O(9) atom to form MgO6 octahedra that share corners with three equivalent Mg(3)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra,  an edgeedge with one V(1)O6 octahedra,  an edgeedge with one V(2)O6 octahedra,  an edgeedge with one V(4)O6 octahedra,  an edgeedge with one V(5)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(6)O6 octahedra, and edges with two equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-9°. In the sixth Mg site, Mg(6) is bonded to one O(10), one O(13), one O(4), one O(7), one O(8), and one O(9) atom to form MgO6 octahedra that share corners with three equivalent V(1)O6 octahedra, corners with three equivalent V(5)O6 octahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one V(2)O6 octahedra,  an edgeedge with one V(4)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, and edges with two equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-7°. In the seventh Mg site, Mg(7) is bonded to one O(12), one O(13), one O(4), one O(6), one O(8), and one O(9) atom to form MgO6 octahedra that share corners with three equivalent V(2)O6 octahedra, corners with three equivalent V(4)O6 octahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one V(1)O6 octahedra,  an edgeedge with one V(5)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, and edges with two equivalent Mg(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-6°. In the eighth Mg site, Mg(8) is bonded to one O(11), one O(15), one O(16), and one O(3) atom to form MgO4 tetrahedra that share  a cornercorner with one Mg(4)O6 octahedra,  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one V(2)O6 octahedra, corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent V(4)O6 octahedra, corners with two equivalent V(5)O6 octahedra, and corners with three equivalent V(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-64°. There are five inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(4), and one O(8) atom to form VO6 octahedra that share corners with three equivalent Mg(6)O6 octahedra,  a cornercorner with one Mg(8)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra,  an edgeedge with one Mg(7)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, and edges with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. In the second V site, V(2) is bonded to one O(1), one O(12), one O(3), one O(4), one O(5), and one O(8) atom to form VO6 octahedra that share corners with three equivalent Mg(7)O6 octahedra,  a cornercorner with one Mg(8)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, and edges with two equivalent V(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 2-6°. In the third V site, V(3) is bonded to one O(1), one O(11), one O(15), one O(16), one O(2), and one O(5) atom to form VO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Mg(8)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one V(1)O6 octahedra,  an edgeedge with one V(2)O6 octahedra,  an edgeedge with one V(4)O6 octahedra, and  an edgeedge with one V(5)O6 octahedra. In the fourth V site, V(4) is bonded to one O(11), one O(13), one O(14), one O(16), one O(6), and one O(9) atom to form VO6 octahedra that share corners with three equivalent Mg(7)O6 octahedra,  a cornercorner with one Mg(1)O4 tetrahedra, corners with two equivalent Mg(8)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, and edges with two equivalent V(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-5°. In the fifth V site, V(5) is bonded to one O(13), one O(14), one O(15), one O(16), one O(7), and one O(9) atom to form VO6 octahedra that share corners with three equivalent Mg(6)O6 octahedra,  a cornercorner with one Mg(1)O4 tetrahedra, corners with two equivalent Mg(8)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra,  an edgeedge with one Mg(7)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, and edges with two equivalent V(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-4°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one V(1), one V(2), and one V(3) atom. In the second O site, O(2) is bonded to one Mg(1), one Mg(4), one V(1), and one V(3) atom to form distorted OMg2V2 trigonal pyramids that share  a cornercorner with one O(4)Mg3V2 square pyramid,  a cornercorner with one O(12)Mg4V square pyramid, corners with two equivalent O(10)Mg4V square pyramids,  a cornercorner with one O(15)Mg2V2 tetrahedra,  a cornercorner with one O(11)Mg2V2 trigonal pyramid,  a cornercorner with one O(5)Mg2V2 trigonal pyramid,  an edgeedge with one O(8)Mg4V2 octahedra, and  an edgeedge with one O(5)Mg2V2 trigonal pyramid. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(4), one Mg(8), one V(1), and one V(2) atom. In the fourth O site, O(4) is bonded to one Mg(2), one Mg(6), one Mg(7), one V(1), and one V(2) atom to form OMg3V2 square pyramids that share  a cornercorner with one O(10)Mg4V square pyramid,  a cornercorner with one O(12)Mg4V square pyramid, corners with three equivalent O(13)Mg3V2 square pyramids,  a cornercorner with one O(2)Mg2V2 trigonal pyramid,  a cornercorner with one O(5)Mg2V2 trigonal pyramid,  an edgeedge with one O(9)Mg4V2 octahedra, edges with two equivalent O(8)Mg4V2 octahedra,  an edgeedge with one O(10)Mg4V square pyramid,  an edgeedge with one O(12)Mg4V square pyramid,  an edgeedge with one O(6)Mg4V square pyramid, and  an edgeedge with one O(7)Mg4V square pyramid. In the fifth O site, O(5) is bonded to one Mg(1), one Mg(4), one V(2), and one V(3) atom to form distorted OMg2V2 trigonal pyramids that share  a cornercorner with one O(4)Mg3V2 square pyramid,  a cornercorner with one O(10)Mg4V square pyramid, corners with two equivalent O(12)Mg4V square pyramids,  a cornercorner with one O(15)Mg2V2 tetrahedra,  a cornercorner with one O(11)Mg2V2 trigonal pyramid,  a cornercorner with one O(2)Mg2V2 trigonal pyramid,  an edgeedge with one O(8)Mg4V2 octahedra, and  an edgeedge with one O(2)Mg2V2 trigonal pyramid. In the sixth O site, O(6) is bonded to one Mg(2), one Mg(3), one Mg(5), one Mg(7), and one V(4) atom to form OMg4V square pyramids that share  a cornercorner with one O(13)Mg3V2 square pyramid,  a cornercorner with one O(7)Mg4V square pyramid, corners with three equivalent O(12)Mg4V square pyramids,  a cornercorner with one O(15)Mg2V2 tetrahedra, corners with two equivalent O(11)Mg2V2 trigonal pyramids,  an edgeedge with one O(8)Mg4V2 octahedra, edges with two equivalent O(9)Mg4V2 octahedra,  an edgeedge with one O(13)Mg3V2 square pyramid,  an edgeedge with one O(4)Mg3V2 square pyramid,  an edgeedge with one O(10)Mg4V square pyramid, and  an edgeedge with one O(7)Mg4V square pyramid. In the seventh O site, O(7) is bonded to one Mg(2), one Mg(3), one Mg(5), one Mg(6), and one V(5) atom to form OMg4V square pyramids that share  a cornercorner with one O(13)Mg3V2 square pyramid,  a cornercorner with one O(6)Mg4V square pyramid, corners with three equivalent O(10)Mg4V square pyramids, corners with two equivalent O(15)Mg2V2 tetrahedra,  a cornercorner with one O(11)Mg2V2 trigonal pyramid,  an edgeedge with one O(8)Mg4V2 octahedra, edges with two equivalent O(9)Mg4V2 octahedra,  an edgeedge with one O(13)Mg3V2 square pyramid,  an edgeedge with one O(4)Mg3V2 square pyramid,  an edgeedge with one O(12)Mg4V square pyramid, and  an edgeedge with one O(6)Mg4V square pyramid. In the eighth O site, O(8) is bonded to one Mg(4), one Mg(5), one Mg(6), one Mg(7), one V(1), and one V(2) atom to form OMg4V2 octahedra that share corners with three equivalent O(9)Mg4V2 octahedra,  an edgeedge with one O(13)Mg3V2 square pyramid,  an edgeedge with one O(6)Mg4V square pyramid,  an edgeedge with one O(7)Mg4V square pyramid, edges with two equivalent O(4)Mg3V2 square pyramids, edges with two equivalent O(10)Mg4V square pyramids, edges with two equivalent O(12)Mg4V square pyramids,  an edgeedge with one O(2)Mg2V2 trigonal pyramid, and  an edgeedge with one O(5)Mg2V2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 2-4°. In the ninth O site, O(9) is bonded to one Mg(3), one Mg(5), one Mg(6), one Mg(7), one V(4), and one V(5) atom to form OMg4V2 octahedra that share corners with three equivalent O(8)Mg4V2 octahedra,  an edgeedge with one O(4)Mg3V2 square pyramid,  an edgeedge with one O(10)Mg4V square pyramid,  an edgeedge with one O(12)Mg4V square pyramid, edges with two equivalent O(13)Mg3V2 square pyramids, edges with two equivalent O(6)Mg4V square pyramids, edges with two equivalent O(7)Mg4V square pyramids,  an edgeedge with one O(15)Mg2V2 tetrahedra, and  an edgeedge with one O(11)Mg2V2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 2-4°. In the tenth O site, O(10) is bonded to one Mg(2), one Mg(4), one Mg(5), one Mg(6), and one V(1) atom to form OMg4V square pyramids that share  a cornercorner with one O(4)Mg3V2 square pyramid,  a cornercorner with one O(12)Mg4V square pyramid, corners with three equivalent O(7)Mg4V square pyramids,  a cornercorner with one O(5)Mg2V2 trigonal pyramid, corners with two equivalent O(2)Mg2V2 trigonal pyramids,  an edgeedge with one O(9)Mg4V2 octahedra, edges with two equivalent O(8)Mg4V2 octahedra,  an edgeedge with one O(13)Mg3V2 square pyramid,  an edgeedge with one O(4)Mg3V2 square pyramid,  an edgeedge with one O(12)Mg4V square pyramid, and  an edgeedge with one O(6)Mg4V square pyramid. In the eleventh O site, O(11) is bonded to one Mg(3), one Mg(8), one V(3), and one V(4) atom to form distorted OMg2V2 trigonal pyramids that share  a cornercorner with one O(13)Mg3V2 square pyramid,  a cornercorner with one O(7)Mg4V square pyramid, corners with two equivalent O(6)Mg4V square pyramids,  a cornercorner with one O(15)Mg2V2 tetrahedra,  a cornercorner with one O(2)Mg2V2 trigonal pyramid,  a cornercorner with one O(5)Mg2V2 trigonal pyramid,  an edgeedge with one O(9)Mg4V2 octahedra, and  an edgeedge with one O(15)Mg2V2 tetrahedra. In the twelfth O site, O(12) is bonded to one Mg(2), one Mg(4), one Mg(5), one Mg(7), and one V(2) atom to form OMg4V square pyramids that share  a cornercorner with one O(4)Mg3V2 square pyramid,  a cornercorner with one O(10)Mg4V square pyramid, corners with three equivalent O(6)Mg4V square pyramids,  a cornercorner with one O(2)Mg2V2 trigonal pyramid, corners with two equivalent O(5)Mg2V2 trigonal pyramids,  an edgeedge with one O(9)Mg4V2 octahedra, edges with two equivalent O(8)Mg4V2 octahedra,  an edgeedge with one O(13)Mg3V2 square pyramid,  an edgeedge with one O(4)Mg3V2 square pyramid,  an edgeedge with one O(10)Mg4V square pyramid, and  an edgeedge with one O(7)Mg4V square pyramid. In the thirteenth O site, O(13) is bonded to one Mg(2), one Mg(6), one Mg(7), one V(4), and one V(5) atom to form OMg3V2 square pyramids that share  a cornercorner with one O(6)Mg4V square pyramid,  a cornercorner with one O(7)Mg4V square pyramid, corners with three equivalent O(4)Mg3V2 square pyramids,  a cornercorner with one O(15)Mg2V2 tetrahedra,  a cornercorner with one O(11)Mg2V2 trigonal pyramid,  an edgeedge with one O(8)Mg4V2 octahedra, edges with two equivalent O(9)Mg4V2 octahedra,  an edgeedge with one O(10)Mg4V square pyramid,  an edgeedge with one O(12)Mg4V square pyramid,  an edgeedge with one O(6)Mg4V square pyramid, and  an edgeedge with one O(7)Mg4V square pyramid. In the fourteenth O site, O(14) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(3), one V(4), and one V(5) atom. In the fifteenth O site, O(15) is bonded to one Mg(3), one Mg(8), one V(3), and one V(5) atom to form distorted OMg2V2 tetrahedra that share  a cornercorner with one O(13)Mg3V2 square pyramid,  a cornercorner with one O(6)Mg4V square pyramid, corners with two equivalent O(7)Mg4V square pyramids,  a cornercorner with one O(11)Mg2V2 trigonal pyramid,  a cornercorner with one O(2)Mg2V2 trigonal pyramid,  a cornercorner with one O(5)Mg2V2 trigonal pyramid,  an edgeedge with one O(9)Mg4V2 octahedra, and  an edgeedge with one O(11)Mg2V2 trigonal pyramid. In the sixteenth O site, O(16) is bonded in a distorted rectangular see-saw-like geometry to one Mg(8), one V(3), one V(4), and one V(5) atom.
Mg8V5O16 crystallizes in the triclinic P1 space group. There are eight inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), one O(14), one O(2), and one O(5) atom to form MgO4 tetrahedra that share  a cornercorner with one Mg(3)O6 octahedra,  a cornercorner with one V(4)O6 octahedra,  a cornercorner with one V(5)O6 octahedra, corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and corners with three equivalent V(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-63°. The Mg(1)-O(1) bond length is 1.98 Å. The Mg(1)-O(14) bond length is 2.04 Å. The Mg(1)-O(2) bond length is 1.98 Å. The Mg(1)-O(5) bond length is 1.97 Å. In the second Mg site, Mg(2) is bonded to one O(10), one O(12), one O(13), one O(4), one O(6), and one O(7) atom to form MgO6 octahedra that share  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one V(1)O6 octahedra,  an edgeedge with one V(2)O6 octahedra,  an edgeedge with one V(4)O6 octahedra,  an edgeedge with one V(5)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, edges with two equivalent Mg(6)O6 octahedra, and edges with two equivalent Mg(7)O6 octahedra. The Mg(2)-O(10) bond length is 2.04 Å. The Mg(2)-O(12) bond length is 2.03 Å. The Mg(2)-O(13) bond length is 2.07 Å. The Mg(2)-O(4) bond length is 2.03 Å. The Mg(2)-O(6) bond length is 2.05 Å. The Mg(2)-O(7) bond length is 2.10 Å. In the third Mg site, Mg(3) is bonded to one O(11), one O(14), one O(15), one O(6), one O(7), and one O(9) atom to form MgO6 octahedra that share corners with three equivalent Mg(5)O6 octahedra,  a cornercorner with one Mg(1)O4 tetrahedra, corners with two equivalent Mg(8)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one Mg(7)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent V(4)O6 octahedra, and edges with two equivalent V(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-9°. The Mg(3)-O(11) bond length is 2.07 Å. The Mg(3)-O(14) bond length is 2.06 Å. The Mg(3)-O(15) bond length is 2.07 Å. The Mg(3)-O(6) bond length is 2.13 Å. The Mg(3)-O(7) bond length is 2.18 Å. The Mg(3)-O(9) bond length is 2.15 Å. In the fourth Mg site, Mg(4) is bonded to one O(10), one O(12), one O(2), one O(3), one O(5), and one O(8) atom to form MgO6 octahedra that share corners with three equivalent Mg(5)O6 octahedra,  a cornercorner with one Mg(8)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one Mg(7)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent V(1)O6 octahedra, and edges with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-6°. The Mg(4)-O(10) bond length is 2.16 Å. The Mg(4)-O(12) bond length is 2.16 Å. The Mg(4)-O(2) bond length is 2.06 Å. The Mg(4)-O(3) bond length is 2.04 Å. The Mg(4)-O(5) bond length is 2.09 Å. The Mg(4)-O(8) bond length is 2.18 Å. In the fifth Mg site, Mg(5) is bonded to one O(10), one O(12), one O(6), one O(7), one O(8), and one O(9) atom to form MgO6 octahedra that share corners with three equivalent Mg(3)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra,  an edgeedge with one V(1)O6 octahedra,  an edgeedge with one V(2)O6 octahedra,  an edgeedge with one V(4)O6 octahedra,  an edgeedge with one V(5)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(6)O6 octahedra, and edges with two equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-9°. The Mg(5)-O(10) bond length is 2.10 Å. The Mg(5)-O(12) bond length is 2.13 Å. The Mg(5)-O(6) bond length is 2.17 Å. The Mg(5)-O(7) bond length is 2.15 Å. The Mg(5)-O(8) bond length is 2.09 Å. The Mg(5)-O(9) bond length is 2.10 Å. In the sixth Mg site, Mg(6) is bonded to one O(10), one O(13), one O(4), one O(7), one O(8), and one O(9) atom to form MgO6 octahedra that share corners with three equivalent V(1)O6 octahedra, corners with three equivalent V(5)O6 octahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one V(2)O6 octahedra,  an edgeedge with one V(4)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, and edges with two equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-7°. The Mg(6)-O(10) bond length is 2.09 Å. The Mg(6)-O(13) bond length is 2.25 Å. The Mg(6)-O(4) bond length is 2.10 Å. The Mg(6)-O(7) bond length is 2.35 Å. The Mg(6)-O(8) bond length is 2.11 Å. The Mg(6)-O(9) bond length is 2.15 Å. In the seventh Mg site, Mg(7) is bonded to one O(12), one O(13), one O(4), one O(6), one O(8), and one O(9) atom to form MgO6 octahedra that share corners with three equivalent V(2)O6 octahedra, corners with three equivalent V(4)O6 octahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one V(1)O6 octahedra,  an edgeedge with one V(5)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, and edges with two equivalent Mg(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-6°. The Mg(7)-O(12) bond length is 2.14 Å. The Mg(7)-O(13) bond length is 2.21 Å. The Mg(7)-O(4) bond length is 2.16 Å. The Mg(7)-O(6) bond length is 2.17 Å. The Mg(7)-O(8) bond length is 2.10 Å. The Mg(7)-O(9) bond length is 2.12 Å. In the eighth Mg site, Mg(8) is bonded to one O(11), one O(15), one O(16), and one O(3) atom to form MgO4 tetrahedra that share  a cornercorner with one Mg(4)O6 octahedra,  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one V(2)O6 octahedra, corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent V(4)O6 octahedra, corners with two equivalent V(5)O6 octahedra, and corners with three equivalent V(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-64°. The Mg(8)-O(11) bond length is 1.98 Å. The Mg(8)-O(15) bond length is 2.03 Å. The Mg(8)-O(16) bond length is 2.01 Å. The Mg(8)-O(3) bond length is 2.00 Å. There are five inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(4), and one O(8) atom to form VO6 octahedra that share corners with three equivalent Mg(6)O6 octahedra,  a cornercorner with one Mg(8)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra,  an edgeedge with one Mg(7)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, and edges with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. The V(1)-O(1) bond length is 2.08 Å. The V(1)-O(10) bond length is 2.06 Å. The V(1)-O(2) bond length is 2.01 Å. The V(1)-O(3) bond length is 1.97 Å. The V(1)-O(4) bond length is 2.16 Å. The V(1)-O(8) bond length is 2.22 Å. In the second V site, V(2) is bonded to one O(1), one O(12), one O(3), one O(4), one O(5), and one O(8) atom to form VO6 octahedra that share corners with three equivalent Mg(7)O6 octahedra,  a cornercorner with one Mg(8)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, and edges with two equivalent V(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 2-6°. The V(2)-O(1) bond length is 2.02 Å. The V(2)-O(12) bond length is 2.05 Å. The V(2)-O(3) bond length is 2.07 Å. The V(2)-O(4) bond length is 2.10 Å. The V(2)-O(5) bond length is 2.01 Å. The V(2)-O(8) bond length is 2.21 Å. In the third V site, V(3) is bonded to one O(1), one O(11), one O(15), one O(16), one O(2), and one O(5) atom to form VO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Mg(8)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one V(1)O6 octahedra,  an edgeedge with one V(2)O6 octahedra,  an edgeedge with one V(4)O6 octahedra, and  an edgeedge with one V(5)O6 octahedra. The V(3)-O(1) bond length is 2.08 Å. The V(3)-O(11) bond length is 2.02 Å. The V(3)-O(15) bond length is 2.10 Å. The V(3)-O(16) bond length is 2.11 Å. The V(3)-O(2) bond length is 2.01 Å. The V(3)-O(5) bond length is 2.00 Å. In the fourth V site, V(4) is bonded to one O(11), one O(13), one O(14), one O(16), one O(6), and one O(9) atom to form VO6 octahedra that share corners with three equivalent Mg(7)O6 octahedra,  a cornercorner with one Mg(1)O4 tetrahedra, corners with two equivalent Mg(8)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, and edges with two equivalent V(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-5°. The V(4)-O(11) bond length is 2.00 Å. The V(4)-O(13) bond length is 2.07 Å. The V(4)-O(14) bond length is 2.09 Å. The V(4)-O(16) bond length is 2.04 Å. The V(4)-O(6) bond length is 2.04 Å. The V(4)-O(9) bond length is 2.19 Å. In the fifth V site, V(5) is bonded to one O(13), one O(14), one O(15), one O(16), one O(7), and one O(9) atom to form VO6 octahedra that share corners with three equivalent Mg(6)O6 octahedra,  a cornercorner with one Mg(1)O4 tetrahedra, corners with two equivalent Mg(8)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra,  an edgeedge with one Mg(7)O6 octahedra,  an edgeedge with one V(3)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, and edges with two equivalent V(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-4°. The V(5)-O(13) bond length is 2.08 Å. The V(5)-O(14) bond length is 1.93 Å. The V(5)-O(15) bond length is 1.91 Å. The V(5)-O(16) bond length is 2.02 Å. The V(5)-O(7) bond length is 1.92 Å. The V(5)-O(9) bond length is 2.21 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one V(1), one V(2), and one V(3) atom. In the second O site, O(2) is bonded to one Mg(1), one Mg(4), one V(1), and one V(3) atom to form distorted OMg2V2 trigonal pyramids that share  a cornercorner with one O(4)Mg3V2 square pyramid,  a cornercorner with one O(12)Mg4V square pyramid, corners with two equivalent O(10)Mg4V square pyramids,  a cornercorner with one O(15)Mg2V2 tetrahedra,  a cornercorner with one O(11)Mg2V2 trigonal pyramid,  a cornercorner with one O(5)Mg2V2 trigonal pyramid,  an edgeedge with one O(8)Mg4V2 octahedra, and  an edgeedge with one O(5)Mg2V2 trigonal pyramid. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(4), one Mg(8), one V(1), and one V(2) atom. In the fourth O site, O(4) is bonded to one Mg(2), one Mg(6), one Mg(7), one V(1), and one V(2) atom to form OMg3V2 square pyramids that share  a cornercorner with one O(10)Mg4V square pyramid,  a cornercorner with one O(12)Mg4V square pyramid, corners with three equivalent O(13)Mg3V2 square pyramids,  a cornercorner with one O(2)Mg2V2 trigonal pyramid,  a cornercorner with one O(5)Mg2V2 trigonal pyramid,  an edgeedge with one O(9)Mg4V2 octahedra, edges with two equivalent O(8)Mg4V2 octahedra,  an edgeedge with one O(10)Mg4V square pyramid,  an edgeedge with one O(12)Mg4V square pyramid,  an edgeedge with one O(6)Mg4V square pyramid, and  an edgeedge with one O(7)Mg4V square pyramid. In the fifth O site, O(5) is bonded to one Mg(1), one Mg(4), one V(2), and one V(3) atom to form distorted OMg2V2 trigonal pyramids that share  a cornercorner with one O(4)Mg3V2 square pyramid,  a cornercorner with one O(10)Mg4V square pyramid, corners with two equivalent O(12)Mg4V square pyramids,  a cornercorner with one O(15)Mg2V2 tetrahedra,  a cornercorner with one O(11)Mg2V2 trigonal pyramid,  a cornercorner with one O(2)Mg2V2 trigonal pyramid,  an edgeedge with one O(8)Mg4V2 octahedra, and  an edgeedge with one O(2)Mg2V2 trigonal pyramid. In the sixth O site, O(6) is bonded to one Mg(2), one Mg(3), one Mg(5), one Mg(7), and one V(4) atom to form OMg4V square pyramids that share  a cornercorner with one O(13)Mg3V2 square pyramid,  a cornercorner with one O(7)Mg4V square pyramid, corners with three equivalent O(12)Mg4V square pyramids,  a cornercorner with one O(15)Mg2V2 tetrahedra, corners with two equivalent O(11)Mg2V2 trigonal pyramids,  an edgeedge with one O(8)Mg4V2 octahedra, edges with two equivalent O(9)Mg4V2 octahedra,  an edgeedge with one O(13)Mg3V2 square pyramid,  an edgeedge with one O(4)Mg3V2 square pyramid,  an edgeedge with one O(10)Mg4V square pyramid, and  an edgeedge with one O(7)Mg4V square pyramid. In the seventh O site, O(7) is bonded to one Mg(2), one Mg(3), one Mg(5), one Mg(6), and one V(5) atom to form OMg4V square pyramids that share  a cornercorner with one O(13)Mg3V2 square pyramid,  a cornercorner with one O(6)Mg4V square pyramid, corners with three equivalent O(10)Mg4V square pyramids, corners with two equivalent O(15)Mg2V2 tetrahedra,  a cornercorner with one O(11)Mg2V2 trigonal pyramid,  an edgeedge with one O(8)Mg4V2 octahedra, edges with two equivalent O(9)Mg4V2 octahedra,  an edgeedge with one O(13)Mg3V2 square pyramid,  an edgeedge with one O(4)Mg3V2 square pyramid,  an edgeedge with one O(12)Mg4V square pyramid, and  an edgeedge with one O(6)Mg4V square pyramid. In the eighth O site, O(8) is bonded to one Mg(4), one Mg(5), one Mg(6), one Mg(7), one V(1), and one V(2) atom to form OMg4V2 octahedra that share corners with three equivalent O(9)Mg4V2 octahedra,  an edgeedge with one O(13)Mg3V2 square pyramid,  an edgeedge with one O(6)Mg4V square pyramid,  an edgeedge with one O(7)Mg4V square pyramid, edges with two equivalent O(4)Mg3V2 square pyramids, edges with two equivalent O(10)Mg4V square pyramids, edges with two equivalent O(12)Mg4V square pyramids,  an edgeedge with one O(2)Mg2V2 trigonal pyramid, and  an edgeedge with one O(5)Mg2V2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 2-4°. In the ninth O site, O(9) is bonded to one Mg(3), one Mg(5), one Mg(6), one Mg(7), one V(4), and one V(5) atom to form OMg4V2 octahedra that share corners with three equivalent O(8)Mg4V2 octahedra,  an edgeedge with one O(4)Mg3V2 square pyramid,  an edgeedge with one O(10)Mg4V square pyramid,  an edgeedge with one O(12)Mg4V square pyramid, edges with two equivalent O(13)Mg3V2 square pyramids, edges with two equivalent O(6)Mg4V square pyramids, edges with two equivalent O(7)Mg4V square pyramids,  an edgeedge with one O(15)Mg2V2 tetrahedra, and  an edgeedge with one O(11)Mg2V2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 2-4°. In the tenth O site, O(10) is bonded to one Mg(2), one Mg(4), one Mg(5), one Mg(6), and one V(1) atom to form OMg4V square pyramids that share  a cornercorner with one O(4)Mg3V2 square pyramid,  a cornercorner with one O(12)Mg4V square pyramid, corners with three equivalent O(7)Mg4V square pyramids,  a cornercorner with one O(5)Mg2V2 trigonal pyramid, corners with two equivalent O(2)Mg2V2 trigonal pyramids,  an edgeedge with one O(9)Mg4V2 octahedra, edges with two equivalent O(8)Mg4V2 octahedra,  an edgeedge with one O(13)Mg3V2 square pyramid,  an edgeedge with one O(4)Mg3V2 square pyramid,  an edgeedge with one O(12)Mg4V square pyramid, and  an edgeedge with one O(6)Mg4V square pyramid. In the eleventh O site, O(11) is bonded to one Mg(3), one Mg(8), one V(3), and one V(4) atom to form distorted OMg2V2 trigonal pyramids that share  a cornercorner with one O(13)Mg3V2 square pyramid,  a cornercorner with one O(7)Mg4V square pyramid, corners with two equivalent O(6)Mg4V square pyramids,  a cornercorner with one O(15)Mg2V2 tetrahedra,  a cornercorner with one O(2)Mg2V2 trigonal pyramid,  a cornercorner with one O(5)Mg2V2 trigonal pyramid,  an edgeedge with one O(9)Mg4V2 octahedra, and  an edgeedge with one O(15)Mg2V2 tetrahedra. In the twelfth O site, O(12) is bonded to one Mg(2), one Mg(4), one Mg(5), one Mg(7), and one V(2) atom to form OMg4V square pyramids that share  a cornercorner with one O(4)Mg3V2 square pyramid,  a cornercorner with one O(10)Mg4V square pyramid, corners with three equivalent O(6)Mg4V square pyramids,  a cornercorner with one O(2)Mg2V2 trigonal pyramid, corners with two equivalent O(5)Mg2V2 trigonal pyramids,  an edgeedge with one O(9)Mg4V2 octahedra, edges with two equivalent O(8)Mg4V2 octahedra,  an edgeedge with one O(13)Mg3V2 square pyramid,  an edgeedge with one O(4)Mg3V2 square pyramid,  an edgeedge with one O(10)Mg4V square pyramid, and  an edgeedge with one O(7)Mg4V square pyramid. In the thirteenth O site, O(13) is bonded to one Mg(2), one Mg(6), one Mg(7), one V(4), and one V(5) atom to form OMg3V2 square pyramids that share  a cornercorner with one O(6)Mg4V square pyramid,  a cornercorner with one O(7)Mg4V square pyramid, corners with three equivalent O(4)Mg3V2 square pyramids,  a cornercorner with one O(15)Mg2V2 tetrahedra,  a cornercorner with one O(11)Mg2V2 trigonal pyramid,  an edgeedge with one O(8)Mg4V2 octahedra, edges with two equivalent O(9)Mg4V2 octahedra,  an edgeedge with one O(10)Mg4V square pyramid,  an edgeedge with one O(12)Mg4V square pyramid,  an edgeedge with one O(6)Mg4V square pyramid, and  an edgeedge with one O(7)Mg4V square pyramid. In the fourteenth O site, O(14) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(3), one V(4), and one V(5) atom. In the fifteenth O site, O(15) is bonded to one Mg(3), one Mg(8), one V(3), and one V(5) atom to form distorted OMg2V2 tetrahedra that share  a cornercorner with one O(13)Mg3V2 square pyramid,  a cornercorner with one O(6)Mg4V square pyramid, corners with two equivalent O(7)Mg4V square pyramids,  a cornercorner with one O(11)Mg2V2 trigonal pyramid,  a cornercorner with one O(2)Mg2V2 trigonal pyramid,  a cornercorner with one O(5)Mg2V2 trigonal pyramid,  an edgeedge with one O(9)Mg4V2 octahedra, and  an edgeedge with one O(11)Mg2V2 trigonal pyramid. In the sixteenth O site, O(16) is bonded in a distorted rectangular see-saw-like geometry to one Mg(8), one V(3), one V(4), and one V(5) atom.