MgTb2Ti2S2O5 crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. Tb(1) is bonded in a 9-coordinate geometry to five equivalent S(1) and four equivalent O(1) atoms. Ti(1) is bonded to one S(1), one O(2), and four equivalent O(1) atoms to form distorted corner-sharing TiSO5 square pyramids. S(1) is bonded to five equivalent Tb(1) and one Ti(1) atom to form a mixture of distorted corner and edge-sharing STb5Ti pentagonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to two equivalent Tb(1) and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a linear geometry to four equivalent Mg(1) and two equivalent Ti(1) atoms.
MgTb2Ti2S2O5 crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. All Mg(1)-O(2) bond lengths are 2.77 Å. Tb(1) is bonded in a 9-coordinate geometry to five equivalent S(1) and four equivalent O(1) atoms. There is one shorter (2.89 Å) and four longer (2.90 Å) Tb(1)-S(1) bond lengths. All Tb(1)-O(1) bond lengths are 2.49 Å. Ti(1) is bonded to one S(1), one O(2), and four equivalent O(1) atoms to form distorted corner-sharing TiSO5 square pyramids. The Ti(1)-S(1) bond length is 2.65 Å. The Ti(1)-O(2) bond length is 1.94 Å. All Ti(1)-O(1) bond lengths are 1.97 Å. S(1) is bonded to five equivalent Tb(1) and one Ti(1) atom to form a mixture of distorted corner and edge-sharing STb5Ti pentagonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to two equivalent Tb(1) and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a linear geometry to four equivalent Mg(1) and two equivalent Ti(1) atoms.