MgTi2(SiO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted MgO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(1)O4 trigonal pyramids, and  an edgeedge with one Si(1)O4 trigonal pyramid. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. In the second Ti site, Ti(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), and one O(8) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form distorted SiO4 trigonal pyramids that share corners with two equivalent Mg(1)O6 octahedra and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-30°. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Mg(1), one Ti(2), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ti(1), one Ti(2), and one Si(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Ti(1), and one Si(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Ti(1), one Ti(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OMgTi2Si tetrahedra. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Ti(1), and one Si(2) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Ti(1), one Ti(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OMgTi2Si tetrahedra. In the seventh O site, O(7) is bonded in a T-shaped geometry to one Mg(1), one Ti(2), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ti(1), one Ti(2), and one Si(2) atom.
MgTi2(SiO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted MgO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(1)O4 trigonal pyramids, and  an edgeedge with one Si(1)O4 trigonal pyramid. The Mg(1)-O(1) bond length is 2.08 Å. The Mg(1)-O(3) bond length is 2.04 Å. The Mg(1)-O(4) bond length is 2.28 Å. The Mg(1)-O(5) bond length is 2.04 Å. The Mg(1)-O(6) bond length is 2.32 Å. The Mg(1)-O(7) bond length is 2.07 Å. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. The Ti(1)-O(2) bond length is 2.13 Å. The Ti(1)-O(3) bond length is 2.11 Å. The Ti(1)-O(4) bond length is 2.08 Å. The Ti(1)-O(5) bond length is 2.11 Å. The Ti(1)-O(6) bond length is 2.07 Å. The Ti(1)-O(8) bond length is 2.13 Å. In the second Ti site, Ti(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), and one O(8) atom. The Ti(2)-O(1) bond length is 2.10 Å. The Ti(2)-O(2) bond length is 2.00 Å. The Ti(2)-O(4) bond length is 2.19 Å. The Ti(2)-O(6) bond length is 2.18 Å. The Ti(2)-O(7) bond length is 2.10 Å. The Ti(2)-O(8) bond length is 2.00 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form distorted SiO4 trigonal pyramids that share corners with two equivalent Mg(1)O6 octahedra and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-30°. The Si(1)-O(1) bond length is 1.63 Å. The Si(1)-O(4) bond length is 1.68 Å. The Si(1)-O(6) bond length is 1.68 Å. The Si(1)-O(7) bond length is 1.63 Å. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 58°. The Si(2)-O(2) bond length is 1.65 Å. The Si(2)-O(3) bond length is 1.62 Å. The Si(2)-O(5) bond length is 1.62 Å. The Si(2)-O(8) bond length is 1.65 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Mg(1), one Ti(2), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ti(1), one Ti(2), and one Si(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Ti(1), and one Si(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Ti(1), one Ti(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OMgTi2Si tetrahedra. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Ti(1), and one Si(2) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Ti(1), one Ti(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OMgTi2Si tetrahedra. In the seventh O site, O(7) is bonded in a T-shaped geometry to one Mg(1), one Ti(2), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ti(1), one Ti(2), and one Si(2) atom.