Fe2TiO5 crystallizes in the orthorhombic Cmc2_1 space group. Ti(1) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Ti(1)O6 octahedra, edges with three equivalent Fe(1)O6 octahedra, and edges with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-56°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, edges with three equivalent Ti(1)O6 octahedra, and edges with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-56°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with three equivalent Ti(1)O6 octahedra, and edges with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-42°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Ti(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ti(1), one Fe(1), and one Fe(2) atom. In the third O site, O(3) is bonded to two equivalent Ti(1), one Fe(1), and one Fe(2) atom to form distorted OTi2Fe2 trigonal pyramids that share  a cornercorner with one O(5)TiFe3 tetrahedra,  a cornercorner with one O(4)TiFe3 trigonal pyramid, corners with two equivalent O(3)Ti2Fe2 trigonal pyramids, edges with two equivalent O(5)TiFe3 tetrahedra, and edges with two equivalent O(4)TiFe3 trigonal pyramids. In the fourth O site, O(4) is bonded to one Ti(1), one Fe(2), and two equivalent Fe(1) atoms to form OTiFe3 trigonal pyramids that share  a cornercorner with one O(5)TiFe3 tetrahedra,  a cornercorner with one O(3)Ti2Fe2 trigonal pyramid, corners with two equivalent O(4)TiFe3 trigonal pyramids, edges with two equivalent O(5)TiFe3 tetrahedra, and edges with two equivalent O(3)Ti2Fe2 trigonal pyramids. In the fifth O site, O(5) is bonded to one Ti(1), one Fe(1), and two equivalent Fe(2) atoms to form distorted OTiFe3 tetrahedra that share corners with two equivalent O(5)TiFe3 tetrahedra,  a cornercorner with one O(3)Ti2Fe2 trigonal pyramid,  a cornercorner with one O(4)TiFe3 trigonal pyramid, edges with two equivalent O(3)Ti2Fe2 trigonal pyramids, and edges with two equivalent O(4)TiFe3 trigonal pyramids.
Fe2TiO5 crystallizes in the orthorhombic Cmc2_1 space group. Ti(1) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Ti(1)O6 octahedra, edges with three equivalent Fe(1)O6 octahedra, and edges with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-56°. The Ti(1)-O(1) bond length is 1.84 Å. The Ti(1)-O(2) bond length is 1.92 Å. The Ti(1)-O(4) bond length is 2.16 Å. The Ti(1)-O(5) bond length is 2.13 Å. Both Ti(1)-O(3) bond lengths are 1.98 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, edges with three equivalent Ti(1)O6 octahedra, and edges with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-56°. The Fe(1)-O(1) bond length is 2.07 Å. The Fe(1)-O(2) bond length is 1.96 Å. The Fe(1)-O(3) bond length is 2.23 Å. The Fe(1)-O(5) bond length is 2.12 Å. Both Fe(1)-O(4) bond lengths are 1.98 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form distorted FeO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with three equivalent Ti(1)O6 octahedra, and edges with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-42°. The Fe(2)-O(1) bond length is 1.99 Å. The Fe(2)-O(2) bond length is 1.96 Å. The Fe(2)-O(3) bond length is 2.16 Å. The Fe(2)-O(4) bond length is 2.13 Å. Both Fe(2)-O(5) bond lengths are 2.03 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Ti(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ti(1), one Fe(1), and one Fe(2) atom. In the third O site, O(3) is bonded to two equivalent Ti(1), one Fe(1), and one Fe(2) atom to form distorted OTi2Fe2 trigonal pyramids that share  a cornercorner with one O(5)TiFe3 tetrahedra,  a cornercorner with one O(4)TiFe3 trigonal pyramid, corners with two equivalent O(3)Ti2Fe2 trigonal pyramids, edges with two equivalent O(5)TiFe3 tetrahedra, and edges with two equivalent O(4)TiFe3 trigonal pyramids. In the fourth O site, O(4) is bonded to one Ti(1), one Fe(2), and two equivalent Fe(1) atoms to form OTiFe3 trigonal pyramids that share  a cornercorner with one O(5)TiFe3 tetrahedra,  a cornercorner with one O(3)Ti2Fe2 trigonal pyramid, corners with two equivalent O(4)TiFe3 trigonal pyramids, edges with two equivalent O(5)TiFe3 tetrahedra, and edges with two equivalent O(3)Ti2Fe2 trigonal pyramids. In the fifth O site, O(5) is bonded to one Ti(1), one Fe(1), and two equivalent Fe(2) atoms to form distorted OTiFe3 tetrahedra that share corners with two equivalent O(5)TiFe3 tetrahedra,  a cornercorner with one O(3)Ti2Fe2 trigonal pyramid,  a cornercorner with one O(4)TiFe3 trigonal pyramid, edges with two equivalent O(3)Ti2Fe2 trigonal pyramids, and edges with two equivalent O(4)TiFe3 trigonal pyramids.