MgPr2Ti4O12 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 6-coordinate geometry to one O(1), one O(4), two equivalent O(2), and two equivalent O(7) atoms. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 8-coordinate geometry to one O(5), one O(8), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms. In the second Pr site, Pr(2) is bonded in a 8-coordinate geometry to one O(1), one O(4), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(8) atom to form corner-sharing TiO5 trigonal bipyramids. In the second Ti site, Ti(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Mg(1), one Pr(2), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded to one Mg(1), one Pr(1), one Ti(1), and one Ti(2) atom to form distorted OPrMgTi2 trigonal pyramids that share corners with three equivalent O(7)Pr2MgTi tetrahedra, corners with two equivalent O(2)PrMgTi2 trigonal pyramids,  an edgeedge with one O(7)Pr2MgTi tetrahedra, and  an edgeedge with one O(4)PrMgTi2 tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(2), one Ti(1), and one Ti(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Pr(2), and two equivalent Ti(2) atoms to form distorted OPrMgTi2 tetrahedra that share corners with two equivalent O(7)Pr2MgTi tetrahedra, edges with two equivalent O(7)Pr2MgTi tetrahedra, and edges with two equivalent O(2)PrMgTi2 trigonal pyramids. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Pr(1) and two equivalent Ti(2) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Pr(2), one Ti(1), and one Ti(2) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Pr(1), one Pr(2), and one Ti(2) atom to form distorted OPr2MgTi tetrahedra that share  a cornercorner with one O(7)Pr2MgTi tetrahedra,  a cornercorner with one O(4)PrMgTi2 tetrahedra, corners with three equivalent O(2)PrMgTi2 trigonal pyramids,  an edgeedge with one O(7)Pr2MgTi tetrahedra,  an edgeedge with one O(4)PrMgTi2 tetrahedra, and  an edgeedge with one O(2)PrMgTi2 trigonal pyramid. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Pr(1) and two equivalent Ti(1) atoms.
MgPr2Ti4O12 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 6-coordinate geometry to one O(1), one O(4), two equivalent O(2), and two equivalent O(7) atoms. The Mg(1)-O(1) bond length is 2.14 Å. The Mg(1)-O(4) bond length is 2.00 Å. Both Mg(1)-O(2) bond lengths are 2.54 Å. Both Mg(1)-O(7) bond lengths are 2.10 Å. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 8-coordinate geometry to one O(5), one O(8), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms. The Pr(1)-O(5) bond length is 2.48 Å. The Pr(1)-O(8) bond length is 2.37 Å. Both Pr(1)-O(2) bond lengths are 2.46 Å. Both Pr(1)-O(3) bond lengths are 2.62 Å. Both Pr(1)-O(7) bond lengths are 2.59 Å. In the second Pr site, Pr(2) is bonded in a 8-coordinate geometry to one O(1), one O(4), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. The Pr(2)-O(1) bond length is 2.54 Å. The Pr(2)-O(4) bond length is 2.48 Å. Both Pr(2)-O(3) bond lengths are 2.48 Å. Both Pr(2)-O(6) bond lengths are 2.52 Å. Both Pr(2)-O(7) bond lengths are 2.49 Å. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(8) atom to form corner-sharing TiO5 trigonal bipyramids. The Ti(1)-O(1) bond length is 2.00 Å. The Ti(1)-O(2) bond length is 1.85 Å. The Ti(1)-O(3) bond length is 1.82 Å. The Ti(1)-O(6) bond length is 2.01 Å. The Ti(1)-O(8) bond length is 1.92 Å. In the second Ti site, Ti(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. The Ti(2)-O(2) bond length is 2.02 Å. The Ti(2)-O(3) bond length is 2.69 Å. The Ti(2)-O(4) bond length is 2.02 Å. The Ti(2)-O(5) bond length is 1.93 Å. The Ti(2)-O(6) bond length is 1.81 Å. The Ti(2)-O(7) bond length is 1.90 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Mg(1), one Pr(2), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded to one Mg(1), one Pr(1), one Ti(1), and one Ti(2) atom to form distorted OPrMgTi2 trigonal pyramids that share corners with three equivalent O(7)Pr2MgTi tetrahedra, corners with two equivalent O(2)PrMgTi2 trigonal pyramids,  an edgeedge with one O(7)Pr2MgTi tetrahedra, and  an edgeedge with one O(4)PrMgTi2 tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(2), one Ti(1), and one Ti(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Pr(2), and two equivalent Ti(2) atoms to form distorted OPrMgTi2 tetrahedra that share corners with two equivalent O(7)Pr2MgTi tetrahedra, edges with two equivalent O(7)Pr2MgTi tetrahedra, and edges with two equivalent O(2)PrMgTi2 trigonal pyramids. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Pr(1) and two equivalent Ti(2) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Pr(2), one Ti(1), and one Ti(2) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Pr(1), one Pr(2), and one Ti(2) atom to form distorted OPr2MgTi tetrahedra that share  a cornercorner with one O(7)Pr2MgTi tetrahedra,  a cornercorner with one O(4)PrMgTi2 tetrahedra, corners with three equivalent O(2)PrMgTi2 trigonal pyramids,  an edgeedge with one O(7)Pr2MgTi tetrahedra,  an edgeedge with one O(4)PrMgTi2 tetrahedra, and  an edgeedge with one O(2)PrMgTi2 trigonal pyramid. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Pr(1) and two equivalent Ti(1) atoms.