MgCe4Ti2O10 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(8), and one O(9) atom to form distorted MgO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra and edges with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-43°. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(3), one O(4), one O(5), one O(6), and one O(9) atom. In the second Ce site, Ce(2) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(3), one O(5), one O(6), and one O(7) atom. In the third Ce site, Ce(3) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(5), one O(6), one O(8), and one O(9) atom. In the fourth Ce site, Ce(4) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(5), one O(6), one O(7), and one O(8) atom. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(10), one O(3), one O(4), one O(7), and one O(8) atom to form TiO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. In the second Ti site, Ti(2) is bonded to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(9) atom to form TiO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra and corners with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-51°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ce(1), one Ce(3), one Ce(4), and one Ti(1) atom to form distorted OCe3MgTi square pyramids that share corners with two equivalent O(10)Ce3MgTi square pyramids,  a cornercorner with one O(6)Ce4Ti trigonal bipyramid, corners with three equivalent O(5)Ce4Ti trigonal bipyramids,  a cornercorner with one O(3)Ce2MgTi trigonal pyramid, corners with three equivalent O(4)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(10)Ce3MgTi square pyramid,  an edgeedge with one O(6)Ce4Ti trigonal bipyramid,  an edgeedge with one O(3)Ce2MgTi trigonal pyramid,  an edgeedge with one O(7)Ce2Ti2 trigonal pyramid, and edges with two equivalent O(8)Ce2MgTi trigonal pyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Ce(2), one Ce(4), and one Ti(2) atom. In the third O site, O(3) is bonded to one Mg(1), one Ce(1), one Ce(2), and one Ti(1) atom to form distorted OCe2MgTi trigonal pyramids that share  a cornercorner with one O(1)Ce3MgTi square pyramid, corners with two equivalent O(5)Ce4Ti trigonal bipyramids, corners with two equivalent O(6)Ce4Ti trigonal bipyramids, corners with two equivalent O(8)Ce2MgTi trigonal pyramids, corners with two equivalent O(4)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(1)Ce3MgTi square pyramid, edges with two equivalent O(10)Ce3MgTi square pyramids, and  an edgeedge with one O(7)Ce2Ti2 trigonal pyramid. In the fourth O site, O(4) is bonded to one Ce(1), one Ce(3), one Ti(1), and one Ti(2) atom to form OCe2Ti2 trigonal pyramids that share corners with three equivalent O(1)Ce3MgTi square pyramids,  a cornercorner with one O(5)Ce4Ti trigonal bipyramid,  a cornercorner with one O(6)Ce4Ti trigonal bipyramid, corners with two equivalent O(3)Ce2MgTi trigonal pyramids, corners with two equivalent O(7)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(10)Ce3MgTi square pyramid,  an edgeedge with one O(5)Ce4Ti trigonal bipyramid,  an edgeedge with one O(6)Ce4Ti trigonal bipyramid, and  an edgeedge with one O(8)Ce2MgTi trigonal pyramid. In the fifth O site, O(5) is bonded to one Ce(1), one Ce(2), one Ce(3), one Ce(4), and one Ti(2) atom to form OCe4Ti trigonal bipyramids that share  a cornercorner with one O(10)Ce3MgTi square pyramid, corners with three equivalent O(1)Ce3MgTi square pyramids,  a cornercorner with one O(6)Ce4Ti trigonal bipyramid,  a cornercorner with one O(4)Ce2Ti2 trigonal pyramid,  a cornercorner with one O(7)Ce2Ti2 trigonal pyramid, corners with two equivalent O(3)Ce2MgTi trigonal pyramids, corners with two equivalent O(8)Ce2MgTi trigonal pyramids,  an edgeedge with one O(10)Ce3MgTi square pyramid, edges with two equivalent O(6)Ce4Ti trigonal bipyramids,  an edgeedge with one O(4)Ce2Ti2 trigonal pyramid, and  an edgeedge with one O(7)Ce2Ti2 trigonal pyramid. In the sixth O site, O(6) is bonded to one Ce(1), one Ce(2), one Ce(3), one Ce(4), and one Ti(2) atom to form OCe4Ti trigonal bipyramids that share  a cornercorner with one O(1)Ce3MgTi square pyramid, corners with three equivalent O(10)Ce3MgTi square pyramids,  a cornercorner with one O(5)Ce4Ti trigonal bipyramid,  a cornercorner with one O(4)Ce2Ti2 trigonal pyramid,  a cornercorner with one O(7)Ce2Ti2 trigonal pyramid, corners with two equivalent O(3)Ce2MgTi trigonal pyramids, corners with two equivalent O(8)Ce2MgTi trigonal pyramids,  an edgeedge with one O(1)Ce3MgTi square pyramid, edges with two equivalent O(5)Ce4Ti trigonal bipyramids,  an edgeedge with one O(4)Ce2Ti2 trigonal pyramid, and  an edgeedge with one O(7)Ce2Ti2 trigonal pyramid. In the seventh O site, O(7) is bonded to one Ce(2), one Ce(4), one Ti(1), and one Ti(2) atom to form OCe2Ti2 trigonal pyramids that share corners with three equivalent O(10)Ce3MgTi square pyramids,  a cornercorner with one O(5)Ce4Ti trigonal bipyramid,  a cornercorner with one O(6)Ce4Ti trigonal bipyramid, corners with two equivalent O(8)Ce2MgTi trigonal pyramids, corners with two equivalent O(4)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(1)Ce3MgTi square pyramid,  an edgeedge with one O(5)Ce4Ti trigonal bipyramid,  an edgeedge with one O(6)Ce4Ti trigonal bipyramid, and  an edgeedge with one O(3)Ce2MgTi trigonal pyramid. In the eighth O site, O(8) is bonded to one Mg(1), one Ce(3), one Ce(4), and one Ti(1) atom to form distorted OCe2MgTi trigonal pyramids that share  a cornercorner with one O(10)Ce3MgTi square pyramid, corners with two equivalent O(5)Ce4Ti trigonal bipyramids, corners with two equivalent O(6)Ce4Ti trigonal bipyramids, corners with two equivalent O(3)Ce2MgTi trigonal pyramids, corners with two equivalent O(7)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(10)Ce3MgTi square pyramid, edges with two equivalent O(1)Ce3MgTi square pyramids, and  an edgeedge with one O(4)Ce2Ti2 trigonal pyramid. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Mg(1), one Ce(1), one Ce(3), and one Ti(2) atom. In the tenth O site, O(10) is bonded to one Mg(1), one Ce(1), one Ce(2), one Ce(4), and one Ti(1) atom to form distorted OCe3MgTi square pyramids that share corners with two equivalent O(1)Ce3MgTi square pyramids,  a cornercorner with one O(5)Ce4Ti trigonal bipyramid, corners with three equivalent O(6)Ce4Ti trigonal bipyramids,  a cornercorner with one O(8)Ce2MgTi trigonal pyramid, corners with three equivalent O(7)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(1)Ce3MgTi square pyramid,  an edgeedge with one O(5)Ce4Ti trigonal bipyramid,  an edgeedge with one O(8)Ce2MgTi trigonal pyramid,  an edgeedge with one O(4)Ce2Ti2 trigonal pyramid, and edges with two equivalent O(3)Ce2MgTi trigonal pyramids.
MgCe4Ti2O10 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(8), and one O(9) atom to form distorted MgO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra and edges with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-43°. The Mg(1)-O(1) bond length is 2.32 Å. The Mg(1)-O(10) bond length is 2.47 Å. The Mg(1)-O(2) bond length is 2.02 Å. The Mg(1)-O(3) bond length is 2.06 Å. The Mg(1)-O(8) bond length is 2.04 Å. The Mg(1)-O(9) bond length is 2.02 Å. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(3), one O(4), one O(5), one O(6), and one O(9) atom. The Ce(1)-O(1) bond length is 2.38 Å. The Ce(1)-O(10) bond length is 2.50 Å. The Ce(1)-O(3) bond length is 2.34 Å. The Ce(1)-O(4) bond length is 2.36 Å. The Ce(1)-O(5) bond length is 2.63 Å. The Ce(1)-O(6) bond length is 2.35 Å. The Ce(1)-O(9) bond length is 2.58 Å. In the second Ce site, Ce(2) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(3), one O(5), one O(6), and one O(7) atom. The Ce(2)-O(10) bond length is 2.63 Å. The Ce(2)-O(2) bond length is 2.31 Å. The Ce(2)-O(3) bond length is 2.32 Å. The Ce(2)-O(5) bond length is 2.64 Å. The Ce(2)-O(6) bond length is 2.37 Å. The Ce(2)-O(7) bond length is 2.38 Å. In the third Ce site, Ce(3) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(5), one O(6), one O(8), and one O(9) atom. The Ce(3)-O(1) bond length is 2.65 Å. The Ce(3)-O(4) bond length is 2.39 Å. The Ce(3)-O(5) bond length is 2.37 Å. The Ce(3)-O(6) bond length is 2.63 Å. The Ce(3)-O(8) bond length is 2.32 Å. The Ce(3)-O(9) bond length is 2.31 Å. In the fourth Ce site, Ce(4) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(5), one O(6), one O(7), and one O(8) atom. The Ce(4)-O(1) bond length is 2.49 Å. The Ce(4)-O(10) bond length is 2.37 Å. The Ce(4)-O(2) bond length is 2.55 Å. The Ce(4)-O(5) bond length is 2.35 Å. The Ce(4)-O(6) bond length is 2.64 Å. The Ce(4)-O(7) bond length is 2.37 Å. The Ce(4)-O(8) bond length is 2.33 Å. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(10), one O(3), one O(4), one O(7), and one O(8) atom to form TiO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. The Ti(1)-O(1) bond length is 2.14 Å. The Ti(1)-O(10) bond length is 2.09 Å. The Ti(1)-O(3) bond length is 2.03 Å. The Ti(1)-O(4) bond length is 2.13 Å. The Ti(1)-O(7) bond length is 2.15 Å. The Ti(1)-O(8) bond length is 2.04 Å. In the second Ti site, Ti(2) is bonded to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(9) atom to form TiO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra and corners with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-51°. The Ti(2)-O(2) bond length is 1.99 Å. The Ti(2)-O(4) bond length is 2.23 Å. The Ti(2)-O(5) bond length is 2.15 Å. The Ti(2)-O(6) bond length is 2.15 Å. The Ti(2)-O(7) bond length is 2.21 Å. The Ti(2)-O(9) bond length is 1.98 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ce(1), one Ce(3), one Ce(4), and one Ti(1) atom to form distorted OCe3MgTi square pyramids that share corners with two equivalent O(10)Ce3MgTi square pyramids,  a cornercorner with one O(6)Ce4Ti trigonal bipyramid, corners with three equivalent O(5)Ce4Ti trigonal bipyramids,  a cornercorner with one O(3)Ce2MgTi trigonal pyramid, corners with three equivalent O(4)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(10)Ce3MgTi square pyramid,  an edgeedge with one O(6)Ce4Ti trigonal bipyramid,  an edgeedge with one O(3)Ce2MgTi trigonal pyramid,  an edgeedge with one O(7)Ce2Ti2 trigonal pyramid, and edges with two equivalent O(8)Ce2MgTi trigonal pyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Ce(2), one Ce(4), and one Ti(2) atom. In the third O site, O(3) is bonded to one Mg(1), one Ce(1), one Ce(2), and one Ti(1) atom to form distorted OCe2MgTi trigonal pyramids that share  a cornercorner with one O(1)Ce3MgTi square pyramid, corners with two equivalent O(5)Ce4Ti trigonal bipyramids, corners with two equivalent O(6)Ce4Ti trigonal bipyramids, corners with two equivalent O(8)Ce2MgTi trigonal pyramids, corners with two equivalent O(4)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(1)Ce3MgTi square pyramid, edges with two equivalent O(10)Ce3MgTi square pyramids, and  an edgeedge with one O(7)Ce2Ti2 trigonal pyramid. In the fourth O site, O(4) is bonded to one Ce(1), one Ce(3), one Ti(1), and one Ti(2) atom to form OCe2Ti2 trigonal pyramids that share corners with three equivalent O(1)Ce3MgTi square pyramids,  a cornercorner with one O(5)Ce4Ti trigonal bipyramid,  a cornercorner with one O(6)Ce4Ti trigonal bipyramid, corners with two equivalent O(3)Ce2MgTi trigonal pyramids, corners with two equivalent O(7)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(10)Ce3MgTi square pyramid,  an edgeedge with one O(5)Ce4Ti trigonal bipyramid,  an edgeedge with one O(6)Ce4Ti trigonal bipyramid, and  an edgeedge with one O(8)Ce2MgTi trigonal pyramid. In the fifth O site, O(5) is bonded to one Ce(1), one Ce(2), one Ce(3), one Ce(4), and one Ti(2) atom to form OCe4Ti trigonal bipyramids that share  a cornercorner with one O(10)Ce3MgTi square pyramid, corners with three equivalent O(1)Ce3MgTi square pyramids,  a cornercorner with one O(6)Ce4Ti trigonal bipyramid,  a cornercorner with one O(4)Ce2Ti2 trigonal pyramid,  a cornercorner with one O(7)Ce2Ti2 trigonal pyramid, corners with two equivalent O(3)Ce2MgTi trigonal pyramids, corners with two equivalent O(8)Ce2MgTi trigonal pyramids,  an edgeedge with one O(10)Ce3MgTi square pyramid, edges with two equivalent O(6)Ce4Ti trigonal bipyramids,  an edgeedge with one O(4)Ce2Ti2 trigonal pyramid, and  an edgeedge with one O(7)Ce2Ti2 trigonal pyramid. In the sixth O site, O(6) is bonded to one Ce(1), one Ce(2), one Ce(3), one Ce(4), and one Ti(2) atom to form OCe4Ti trigonal bipyramids that share  a cornercorner with one O(1)Ce3MgTi square pyramid, corners with three equivalent O(10)Ce3MgTi square pyramids,  a cornercorner with one O(5)Ce4Ti trigonal bipyramid,  a cornercorner with one O(4)Ce2Ti2 trigonal pyramid,  a cornercorner with one O(7)Ce2Ti2 trigonal pyramid, corners with two equivalent O(3)Ce2MgTi trigonal pyramids, corners with two equivalent O(8)Ce2MgTi trigonal pyramids,  an edgeedge with one O(1)Ce3MgTi square pyramid, edges with two equivalent O(5)Ce4Ti trigonal bipyramids,  an edgeedge with one O(4)Ce2Ti2 trigonal pyramid, and  an edgeedge with one O(7)Ce2Ti2 trigonal pyramid. In the seventh O site, O(7) is bonded to one Ce(2), one Ce(4), one Ti(1), and one Ti(2) atom to form OCe2Ti2 trigonal pyramids that share corners with three equivalent O(10)Ce3MgTi square pyramids,  a cornercorner with one O(5)Ce4Ti trigonal bipyramid,  a cornercorner with one O(6)Ce4Ti trigonal bipyramid, corners with two equivalent O(8)Ce2MgTi trigonal pyramids, corners with two equivalent O(4)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(1)Ce3MgTi square pyramid,  an edgeedge with one O(5)Ce4Ti trigonal bipyramid,  an edgeedge with one O(6)Ce4Ti trigonal bipyramid, and  an edgeedge with one O(3)Ce2MgTi trigonal pyramid. In the eighth O site, O(8) is bonded to one Mg(1), one Ce(3), one Ce(4), and one Ti(1) atom to form distorted OCe2MgTi trigonal pyramids that share  a cornercorner with one O(10)Ce3MgTi square pyramid, corners with two equivalent O(5)Ce4Ti trigonal bipyramids, corners with two equivalent O(6)Ce4Ti trigonal bipyramids, corners with two equivalent O(3)Ce2MgTi trigonal pyramids, corners with two equivalent O(7)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(10)Ce3MgTi square pyramid, edges with two equivalent O(1)Ce3MgTi square pyramids, and  an edgeedge with one O(4)Ce2Ti2 trigonal pyramid. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Mg(1), one Ce(1), one Ce(3), and one Ti(2) atom. In the tenth O site, O(10) is bonded to one Mg(1), one Ce(1), one Ce(2), one Ce(4), and one Ti(1) atom to form distorted OCe3MgTi square pyramids that share corners with two equivalent O(1)Ce3MgTi square pyramids,  a cornercorner with one O(5)Ce4Ti trigonal bipyramid, corners with three equivalent O(6)Ce4Ti trigonal bipyramids,  a cornercorner with one O(8)Ce2MgTi trigonal pyramid, corners with three equivalent O(7)Ce2Ti2 trigonal pyramids,  an edgeedge with one O(1)Ce3MgTi square pyramid,  an edgeedge with one O(5)Ce4Ti trigonal bipyramid,  an edgeedge with one O(8)Ce2MgTi trigonal pyramid,  an edgeedge with one O(4)Ce2Ti2 trigonal pyramid, and edges with two equivalent O(3)Ce2MgTi trigonal pyramids.