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Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
CaFeTi2O6 crystallizes in the tetragonal P4_2/nmc space group. The structure is three-dimensional. Ca2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ca–O bond distances ranging from 2.36–2.75 Å. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six equivalent TiO6 octahedra and corners with two equivalent FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 30–37°. There are a spread of Ti–O bond distances ranging from 1.96–2.00 Å. There are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to four equivalent O2- atoms to form distorted FeO4 tetrahedra that share corners with eight equivalent TiO6 octahedra. The corner-sharing octahedral tilt angles are 73°. All Fe–O bond lengths are 2.08 Å. In the second Fe2+ site, Fe2+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Fe–O bond lengths are 2.07 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+, two equivalent Ti4+, and one Fe2+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Ti4+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two equivalent Ti4+, and one Fe2+ atom.
Ca3TiFe2O8 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.87 Å. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.48 Å. In the third Ca2+ site, Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.41–2.99 Å. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with five equivalent FeO6 octahedra and a cornercorner with one FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 16–26°. There are a spread of Ti–O bond distances ranging from 1.87–2.24 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share a cornercorner with one TiO6 octahedra, a cornercorner with one FeO6 octahedra, and corners with two equivalent FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–43°. There are a spread of Fe–O bond distances ranging from 1.87–1.96 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with five equivalent TiO6 octahedra and a cornercorner with one FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 16–26°. There are a spread of Fe–O bond distances ranging from 1.99–2.15 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four Ca2+, one Ti4+, and one Fe3+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+, one Ti4+, and one Fe3+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+, one Ti4+, and one Fe3+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+, one Ti4+, and one Fe3+ atom. In the fifth O2- site, O2- is bonded to two Ca2+ and two equivalent Fe3+ atoms to form distorted corner-sharing OCa2Fe2 tetrahedra. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Fe3+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Fe3+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Ca2+, one Ti4+, and one Fe3+ atom.