MgV8(OF)8 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent F(1) atoms to form MgO4F2 octahedra that share corners with four equivalent V(1)O3F3 octahedra, edges with two equivalent V(5)O2F4 octahedra, edges with two equivalent V(4)O3F3 octahedra, and faces with two equivalent V(3)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-46°. There are six inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(3), one O(4), one F(2), one F(3), and one F(4) atom to form VO3F3 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with two equivalent V(5)O2F4 octahedra, corners with two equivalent V(6)O2F4 octahedra, corners with four equivalent V(4)O3F3 octahedra,  an edgeedge with one V(2)O4F2 octahedra, and  an edgeedge with one V(3)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 41-57°. In the second V site, V(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent F(4) atoms to form VO4F2 octahedra that share corners with four equivalent V(6)O2F4 octahedra, corners with four equivalent V(4)O3F3 octahedra, and edges with two equivalent V(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-58°. In the third V site, V(3) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent F(1) atoms to form VO4F2 octahedra that share corners with four equivalent V(5)O2F4 octahedra, corners with four equivalent V(4)O3F3 octahedra, edges with two equivalent V(1)O3F3 octahedra, and faces with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 44-50°. In the fourth V site, V(4) is bonded to one O(1), one O(2), one O(4), one F(1), one F(2), and one F(3) atom to form distorted VO3F3 octahedra that share corners with two equivalent V(2)O4F2 octahedra, corners with two equivalent V(3)O4F2 octahedra, corners with four equivalent V(1)O3F3 octahedra,  an edgeedge with one Mg(1)O4F2 octahedra,  an edgeedge with one V(5)O2F4 octahedra, and  an edgeedge with one V(6)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 41-58°. In the fifth V site, V(5) is bonded to two equivalent O(3), two equivalent F(1), and two equivalent F(2) atoms to form VO2F4 octahedra that share corners with four equivalent V(1)O3F3 octahedra, corners with four equivalent V(3)O4F2 octahedra, edges with two equivalent Mg(1)O4F2 octahedra, and edges with two equivalent V(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-57°. In the sixth V site, V(6) is bonded to two equivalent O(1), two equivalent F(3), and two equivalent F(4) atoms to form VO2F4 octahedra that share corners with four equivalent V(1)O3F3 octahedra, corners with four equivalent V(2)O4F2 octahedra, and edges with two equivalent V(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one V(2), one V(4), and one V(6) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one V(1), one V(2), and one V(4) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one V(1), one V(3), and one V(5) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one V(1), one V(3), and one V(4) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one V(3), one V(4), and one V(5) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one V(1), one V(4), and one V(5) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one V(1), one V(4), and one V(6) atom. In the fourth F site, F(4) is bonded in a trigonal planar geometry to one V(1), one V(2), and one V(6) atom.
MgV8(OF)8 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent F(1) atoms to form MgO4F2 octahedra that share corners with four equivalent V(1)O3F3 octahedra, edges with two equivalent V(5)O2F4 octahedra, edges with two equivalent V(4)O3F3 octahedra, and faces with two equivalent V(3)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-46°. Both Mg(1)-O(3) bond lengths are 2.05 Å. Both Mg(1)-O(4) bond lengths are 2.10 Å. Both Mg(1)-F(1) bond lengths are 1.96 Å. There are six inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(3), one O(4), one F(2), one F(3), and one F(4) atom to form VO3F3 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with two equivalent V(5)O2F4 octahedra, corners with two equivalent V(6)O2F4 octahedra, corners with four equivalent V(4)O3F3 octahedra,  an edgeedge with one V(2)O4F2 octahedra, and  an edgeedge with one V(3)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 41-57°. The V(1)-O(2) bond length is 1.96 Å. The V(1)-O(3) bond length is 2.06 Å. The V(1)-O(4) bond length is 2.15 Å. The V(1)-F(2) bond length is 2.08 Å. The V(1)-F(3) bond length is 2.05 Å. The V(1)-F(4) bond length is 2.08 Å. In the second V site, V(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent F(4) atoms to form VO4F2 octahedra that share corners with four equivalent V(6)O2F4 octahedra, corners with four equivalent V(4)O3F3 octahedra, and edges with two equivalent V(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-58°. Both V(2)-O(1) bond lengths are 2.06 Å. Both V(2)-O(2) bond lengths are 2.09 Å. Both V(2)-F(4) bond lengths are 2.07 Å. In the third V site, V(3) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent F(1) atoms to form VO4F2 octahedra that share corners with four equivalent V(5)O2F4 octahedra, corners with four equivalent V(4)O3F3 octahedra, edges with two equivalent V(1)O3F3 octahedra, and faces with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 44-50°. Both V(3)-O(3) bond lengths are 1.95 Å. Both V(3)-O(4) bond lengths are 2.03 Å. Both V(3)-F(1) bond lengths are 2.14 Å. In the fourth V site, V(4) is bonded to one O(1), one O(2), one O(4), one F(1), one F(2), and one F(3) atom to form distorted VO3F3 octahedra that share corners with two equivalent V(2)O4F2 octahedra, corners with two equivalent V(3)O4F2 octahedra, corners with four equivalent V(1)O3F3 octahedra,  an edgeedge with one Mg(1)O4F2 octahedra,  an edgeedge with one V(5)O2F4 octahedra, and  an edgeedge with one V(6)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 41-58°. The V(4)-O(1) bond length is 1.85 Å. The V(4)-O(2) bond length is 2.02 Å. The V(4)-O(4) bond length is 2.15 Å. The V(4)-F(1) bond length is 2.32 Å. The V(4)-F(2) bond length is 2.10 Å. The V(4)-F(3) bond length is 2.15 Å. In the fifth V site, V(5) is bonded to two equivalent O(3), two equivalent F(1), and two equivalent F(2) atoms to form VO2F4 octahedra that share corners with four equivalent V(1)O3F3 octahedra, corners with four equivalent V(3)O4F2 octahedra, edges with two equivalent Mg(1)O4F2 octahedra, and edges with two equivalent V(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-57°. Both V(5)-O(3) bond lengths are 2.08 Å. Both V(5)-F(1) bond lengths are 2.12 Å. Both V(5)-F(2) bond lengths are 2.14 Å. In the sixth V site, V(6) is bonded to two equivalent O(1), two equivalent F(3), and two equivalent F(4) atoms to form VO2F4 octahedra that share corners with four equivalent V(1)O3F3 octahedra, corners with four equivalent V(2)O4F2 octahedra, and edges with two equivalent V(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. Both V(6)-O(1) bond lengths are 2.13 Å. Both V(6)-F(3) bond lengths are 2.13 Å. Both V(6)-F(4) bond lengths are 2.08 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one V(2), one V(4), and one V(6) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one V(1), one V(2), and one V(4) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one V(1), one V(3), and one V(5) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one V(1), one V(3), and one V(4) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one V(3), one V(4), and one V(5) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one V(1), one V(4), and one V(5) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one V(1), one V(4), and one V(6) atom. In the fourth F site, F(4) is bonded in a trigonal planar geometry to one V(1), one V(2), and one V(6) atom.