MgSc4Ti2O10 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(4), one O(6), and two equivalent O(5) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, corners with two equivalent Sc(4)O5 trigonal bipyramids, edges with two equivalent Ti(2)O6 octahedra, and edges with three equivalent Sc(2)O6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are four inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(5), one O(8), and two equivalent O(10) atoms. In the second Sc site, Sc(2) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(6) atoms to form distorted ScO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Sc(2)O6 octahedra,  a cornercorner with one Ti(1)O5 trigonal bipyramid, corners with three equivalent Sc(4)O5 trigonal bipyramids, edges with two equivalent Ti(2)O6 octahedra, and edges with three equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-28°. In the third Sc site, Sc(3) is bonded in a 6-coordinate geometry to one O(10), one O(7), one O(8), one O(9), and two equivalent O(3) atoms. In the fourth Sc site, Sc(4) is bonded to one O(1), one O(7), one O(9), and two equivalent O(4) atoms to form ScO5 trigonal bipyramids that share corners with three equivalent Sc(2)O6 octahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, corners with two equivalent Sc(4)O5 trigonal bipyramids, corners with two equivalent Ti(1)O5 trigonal bipyramids, and  an edgeedge with one Ti(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 40-72°. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(3), one O(9), and two equivalent O(7) atoms to form TiO5 trigonal bipyramids that share  a cornercorner with one Sc(2)O6 octahedra, corners with two equivalent Sc(4)O5 trigonal bipyramids, corners with two equivalent Ti(1)O5 trigonal bipyramids, and  an edgeedge with one Sc(4)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 59°. In the second Ti site, Ti(2) is bonded to one O(10), one O(5), one O(6), one O(8), and two equivalent O(2) atoms to form TiO6 octahedra that share  a cornercorner with one Sc(2)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, edges with two equivalent Sc(2)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-21°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Sc(2), one Sc(4), and one Ti(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), one Sc(1), one Sc(2), and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded to one Sc(1), two equivalent Sc(3), and one Ti(1) atom to form distorted OSc3Ti tetrahedra that share corners with two equivalent O(3)Sc3Ti tetrahedra,  a cornercorner with one O(5)Mg2Sc2Ti trigonal bipyramid, edges with two equivalent O(7)Sc2Ti2 trigonal pyramids, and edges with two equivalent O(10)Sc3Ti trigonal pyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Sc(2), and two equivalent Sc(4) atoms to form OMgSc3 tetrahedra that share corners with two equivalent O(4)MgSc3 tetrahedra, corners with three equivalent O(5)Mg2Sc2Ti trigonal bipyramids, and corners with two equivalent O(7)Sc2Ti2 trigonal pyramids. In the fifth O site, O(5) is bonded to two equivalent Mg(1), one Sc(1), one Sc(2), and one Ti(2) atom to form OMg2Sc2Ti trigonal bipyramids that share  a cornercorner with one O(3)Sc3Ti tetrahedra, corners with three equivalent O(4)MgSc3 tetrahedra, corners with two equivalent O(5)Mg2Sc2Ti trigonal bipyramids, and corners with three equivalent O(10)Sc3Ti trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted see-saw-like geometry to one Mg(1), two equivalent Sc(2), and one Ti(2) atom. In the seventh O site, O(7) is bonded to one Sc(3), one Sc(4), and two equivalent Ti(1) atoms to form OSc2Ti2 trigonal pyramids that share corners with two equivalent O(4)MgSc3 tetrahedra,  a cornercorner with one O(10)Sc3Ti trigonal pyramid, corners with two equivalent O(7)Sc2Ti2 trigonal pyramids, and edges with two equivalent O(3)Sc3Ti tetrahedra. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Sc(1), one Sc(3), and one Ti(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Sc(3), one Sc(4), and one Ti(1) atom. In the tenth O site, O(10) is bonded to one Sc(3), two equivalent Sc(1), and one Ti(2) atom to form OSc3Ti trigonal pyramids that share corners with three equivalent O(5)Mg2Sc2Ti trigonal bipyramids,  a cornercorner with one O(7)Sc2Ti2 trigonal pyramid, corners with two equivalent O(10)Sc3Ti trigonal pyramids, and edges with two equivalent O(3)Sc3Ti tetrahedra.
MgSc4Ti2O10 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(4), one O(6), and two equivalent O(5) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, corners with two equivalent Sc(4)O5 trigonal bipyramids, edges with two equivalent Ti(2)O6 octahedra, and edges with three equivalent Sc(2)O6 octahedra. The corner-sharing octahedral tilt angles are 58°. The Mg(1)-O(2) bond length is 2.19 Å. The Mg(1)-O(4) bond length is 2.14 Å. The Mg(1)-O(6) bond length is 2.10 Å. Both Mg(1)-O(5) bond lengths are 2.06 Å. There are four inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(5), one O(8), and two equivalent O(10) atoms. The Sc(1)-O(2) bond length is 2.80 Å. The Sc(1)-O(3) bond length is 2.20 Å. The Sc(1)-O(5) bond length is 2.20 Å. The Sc(1)-O(8) bond length is 1.97 Å. Both Sc(1)-O(10) bond lengths are 2.06 Å. In the second Sc site, Sc(2) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(6) atoms to form distorted ScO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Sc(2)O6 octahedra,  a cornercorner with one Ti(1)O5 trigonal bipyramid, corners with three equivalent Sc(4)O5 trigonal bipyramids, edges with two equivalent Ti(2)O6 octahedra, and edges with three equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-28°. The Sc(2)-O(1) bond length is 1.99 Å. The Sc(2)-O(2) bond length is 2.21 Å. The Sc(2)-O(4) bond length is 2.10 Å. The Sc(2)-O(5) bond length is 2.39 Å. Both Sc(2)-O(6) bond lengths are 2.01 Å. In the third Sc site, Sc(3) is bonded in a 6-coordinate geometry to one O(10), one O(7), one O(8), one O(9), and two equivalent O(3) atoms. The Sc(3)-O(10) bond length is 2.26 Å. The Sc(3)-O(7) bond length is 2.22 Å. The Sc(3)-O(8) bond length is 2.06 Å. The Sc(3)-O(9) bond length is 2.08 Å. Both Sc(3)-O(3) bond lengths are 2.10 Å. In the fourth Sc site, Sc(4) is bonded to one O(1), one O(7), one O(9), and two equivalent O(4) atoms to form ScO5 trigonal bipyramids that share corners with three equivalent Sc(2)O6 octahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, corners with two equivalent Sc(4)O5 trigonal bipyramids, corners with two equivalent Ti(1)O5 trigonal bipyramids, and  an edgeedge with one Ti(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 40-72°. The Sc(4)-O(1) bond length is 2.00 Å. The Sc(4)-O(7) bond length is 2.24 Å. The Sc(4)-O(9) bond length is 2.03 Å. There is one shorter (2.16 Å) and one longer (2.19 Å) Sc(4)-O(4) bond length. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(3), one O(9), and two equivalent O(7) atoms to form TiO5 trigonal bipyramids that share  a cornercorner with one Sc(2)O6 octahedra, corners with two equivalent Sc(4)O5 trigonal bipyramids, corners with two equivalent Ti(1)O5 trigonal bipyramids, and  an edgeedge with one Sc(4)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 59°. The Ti(1)-O(1) bond length is 2.01 Å. The Ti(1)-O(3) bond length is 2.09 Å. The Ti(1)-O(9) bond length is 1.89 Å. There is one shorter (2.04 Å) and one longer (2.14 Å) Ti(1)-O(7) bond length. In the second Ti site, Ti(2) is bonded to one O(10), one O(5), one O(6), one O(8), and two equivalent O(2) atoms to form TiO6 octahedra that share  a cornercorner with one Sc(2)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, edges with two equivalent Sc(2)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-21°. The Ti(2)-O(10) bond length is 2.09 Å. The Ti(2)-O(5) bond length is 2.18 Å. The Ti(2)-O(6) bond length is 2.21 Å. The Ti(2)-O(8) bond length is 1.96 Å. Both Ti(2)-O(2) bond lengths are 1.98 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Sc(2), one Sc(4), and one Ti(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), one Sc(1), one Sc(2), and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded to one Sc(1), two equivalent Sc(3), and one Ti(1) atom to form distorted OSc3Ti tetrahedra that share corners with two equivalent O(3)Sc3Ti tetrahedra,  a cornercorner with one O(5)Mg2Sc2Ti trigonal bipyramid, edges with two equivalent O(7)Sc2Ti2 trigonal pyramids, and edges with two equivalent O(10)Sc3Ti trigonal pyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Sc(2), and two equivalent Sc(4) atoms to form OMgSc3 tetrahedra that share corners with two equivalent O(4)MgSc3 tetrahedra, corners with three equivalent O(5)Mg2Sc2Ti trigonal bipyramids, and corners with two equivalent O(7)Sc2Ti2 trigonal pyramids. In the fifth O site, O(5) is bonded to two equivalent Mg(1), one Sc(1), one Sc(2), and one Ti(2) atom to form OMg2Sc2Ti trigonal bipyramids that share  a cornercorner with one O(3)Sc3Ti tetrahedra, corners with three equivalent O(4)MgSc3 tetrahedra, corners with two equivalent O(5)Mg2Sc2Ti trigonal bipyramids, and corners with three equivalent O(10)Sc3Ti trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted see-saw-like geometry to one Mg(1), two equivalent Sc(2), and one Ti(2) atom. In the seventh O site, O(7) is bonded to one Sc(3), one Sc(4), and two equivalent Ti(1) atoms to form OSc2Ti2 trigonal pyramids that share corners with two equivalent O(4)MgSc3 tetrahedra,  a cornercorner with one O(10)Sc3Ti trigonal pyramid, corners with two equivalent O(7)Sc2Ti2 trigonal pyramids, and edges with two equivalent O(3)Sc3Ti tetrahedra. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Sc(1), one Sc(3), and one Ti(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Sc(3), one Sc(4), and one Ti(1) atom. In the tenth O site, O(10) is bonded to one Sc(3), two equivalent Sc(1), and one Ti(2) atom to form OSc3Ti trigonal pyramids that share corners with three equivalent O(5)Mg2Sc2Ti trigonal bipyramids,  a cornercorner with one O(7)Sc2Ti2 trigonal pyramid, corners with two equivalent O(10)Sc3Ti trigonal pyramids, and edges with two equivalent O(3)Sc3Ti tetrahedra.