Sm2Ti2O5 crystallizes in the orthorhombic Imma space group. Sm(1) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(3), and three equivalent O(2) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 30°. In the second Ti site, Ti(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sm(1) and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to three equivalent Sm(1), one Ti(1), and one Ti(2) atom. In the third O site, O(3) is bonded to four equivalent Sm(1) and two equivalent Ti(2) atoms to form face-sharing OSm4Ti2 octahedra.
Sm2Ti2O5 crystallizes in the orthorhombic Imma space group. Sm(1) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(3), and three equivalent O(2) atoms. Both Sm(1)-O(1) bond lengths are 2.44 Å. Both Sm(1)-O(3) bond lengths are 2.59 Å. There is one shorter (2.36 Å) and two longer (2.78 Å) Sm(1)-O(2) bond lengths. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 30°. Both Ti(1)-O(2) bond lengths are 2.02 Å. All Ti(1)-O(1) bond lengths are 2.01 Å. In the second Ti site, Ti(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. Both Ti(2)-O(2) bond lengths are 1.95 Å. Both Ti(2)-O(3) bond lengths are 2.15 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sm(1) and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to three equivalent Sm(1), one Ti(1), and one Ti(2) atom. In the third O site, O(3) is bonded to four equivalent Sm(1) and two equivalent Ti(2) atoms to form face-sharing OSm4Ti2 octahedra.