MgTiV3O8 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(6) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent Mg(1)O5 trigonal bipyramids,  an edgeedge with one V(1)O6 octahedra, edges with two equivalent Ti(1)O6 octahedra, and edges with two equivalent V(2)O6 octahedra. Ti(1) is bonded to one O(5), one O(6), one O(7), one O(8), and two equivalent O(2) atoms to form TiO6 octahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one V(2)O6 octahedra, corners with two equivalent Ti(1)O6 octahedra,  an edgeedge with one V(2)O6 octahedra, edges with two equivalent V(1)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 9-22°. There are three inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(8) atoms to form VO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent V(1)O6 octahedra,  an edgeedge with one V(2)O6 octahedra, edges with two equivalent Ti(1)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 22-28°. In the second V site, V(2) is bonded to one O(4), one O(5), one O(6), one O(7), and two equivalent O(1) atoms to form distorted VO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra,  an edgeedge with one Ti(1)O6 octahedra,  an edgeedge with one V(1)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 9-32°. In the third V site, V(3) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), and two equivalent O(7) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one V(3), and two equivalent V(2) atoms to form OMgV3 trigonal pyramids that share corners with two equivalent O(1)MgV3 trigonal pyramids and edges with two equivalent O(7)TiV3 trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), two equivalent Ti(1), and one V(1) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Mg(1), one V(1), and one V(3) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one V(1), one V(2), and one V(3) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Ti(1), one V(1), and one V(2) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1), one Ti(1), and one V(2) atom. In the seventh O site, O(7) is bonded to one Ti(1), one V(2), and two equivalent V(3) atoms to form OTiV3 trigonal pyramids that share corners with two equivalent O(7)TiV3 trigonal pyramids and edges with two equivalent O(1)MgV3 trigonal pyramids. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Ti(1) and two equivalent V(1) atoms.
MgTiV3O8 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(6) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent Mg(1)O5 trigonal bipyramids,  an edgeedge with one V(1)O6 octahedra, edges with two equivalent Ti(1)O6 octahedra, and edges with two equivalent V(2)O6 octahedra. The Mg(1)-O(1) bond length is 1.97 Å. The Mg(1)-O(2) bond length is 2.05 Å. The Mg(1)-O(3) bond length is 2.17 Å. Both Mg(1)-O(6) bond lengths are 1.99 Å. Ti(1) is bonded to one O(5), one O(6), one O(7), one O(8), and two equivalent O(2) atoms to form TiO6 octahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one V(2)O6 octahedra, corners with two equivalent Ti(1)O6 octahedra,  an edgeedge with one V(2)O6 octahedra, edges with two equivalent V(1)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 9-22°. The Ti(1)-O(5) bond length is 1.92 Å. The Ti(1)-O(6) bond length is 1.94 Å. The Ti(1)-O(7) bond length is 2.18 Å. The Ti(1)-O(8) bond length is 1.95 Å. Both Ti(1)-O(2) bond lengths are 1.96 Å. There are three inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(8) atoms to form VO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent V(1)O6 octahedra,  an edgeedge with one V(2)O6 octahedra, edges with two equivalent Ti(1)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 22-28°. The V(1)-O(2) bond length is 2.17 Å. The V(1)-O(3) bond length is 2.18 Å. The V(1)-O(4) bond length is 2.09 Å. The V(1)-O(5) bond length is 1.92 Å. Both V(1)-O(8) bond lengths are 2.00 Å. In the second V site, V(2) is bonded to one O(4), one O(5), one O(6), one O(7), and two equivalent O(1) atoms to form distorted VO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra,  an edgeedge with one Ti(1)O6 octahedra,  an edgeedge with one V(1)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 9-32°. The V(2)-O(4) bond length is 1.92 Å. The V(2)-O(5) bond length is 2.02 Å. The V(2)-O(6) bond length is 2.35 Å. The V(2)-O(7) bond length is 2.16 Å. Both V(2)-O(1) bond lengths are 2.02 Å. In the third V site, V(3) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), and two equivalent O(7) atoms. The V(3)-O(1) bond length is 2.03 Å. The V(3)-O(3) bond length is 1.72 Å. The V(3)-O(4) bond length is 1.90 Å. Both V(3)-O(7) bond lengths are 2.06 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one V(3), and two equivalent V(2) atoms to form OMgV3 trigonal pyramids that share corners with two equivalent O(1)MgV3 trigonal pyramids and edges with two equivalent O(7)TiV3 trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), two equivalent Ti(1), and one V(1) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Mg(1), one V(1), and one V(3) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one V(1), one V(2), and one V(3) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Ti(1), one V(1), and one V(2) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1), one Ti(1), and one V(2) atom. In the seventh O site, O(7) is bonded to one Ti(1), one V(2), and two equivalent V(3) atoms to form OTiV3 trigonal pyramids that share corners with two equivalent O(7)TiV3 trigonal pyramids and edges with two equivalent O(1)MgV3 trigonal pyramids. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Ti(1) and two equivalent V(1) atoms.