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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
Sr2(FeO2)3 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.52–2.96 Å. There are two inequivalent Fe+2.67+ sites. In the first Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four equivalent FeO6 octahedra and corners with two equivalent FeO4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Fe–O bond distances ranging from 1.97–2.20 Å. In the second Fe+2.67+ site, Fe+2.67+ is bonded to four O2- atoms to form FeO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with four equivalent FeO4 tetrahedra, and an edgeedge with one FeO4 tetrahedra. The corner-sharing octahedral tilt angles are 22°. There are a spread of Fe–O bond distances ranging from 1.90–2.02 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Sr2+ and three equivalent Fe+2.67+ atoms. In the second O2- site, O2- is bonded to four equivalent Sr2+ and two equivalent Fe+2.67+ atoms to form a mixture of distorted corner, edge, and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third O2- site, O2- is bonded to four equivalent Sr2+ and two equivalent Fe+2.67+ atoms to form a mixture of distorted corner, edge, and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles are 2°. In the fourth O2- site, O2- is bonded to four equivalent Sr2+ and two equivalent Fe+2.67+ atoms to form a mixture of corner, edge, and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent Sr2+ and two Fe+2.67+ atoms.
BaSr(FeO2)4 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.67–3.15 Å. Sr2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sr–O bond distances ranging from 2.56–3.03 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.87–1.92 Å. In the second Fe3+ site, Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. There is one shorter (1.90 Å) and three longer (1.91 Å) Fe–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Sr2+, and two equivalent Fe3+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+, one Sr2+, and two equivalent Fe3+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to three equivalent Ba2+ and two equivalent Fe3+ atoms. In the fourth O2- site, O2- is bonded to one Ba2+, one Sr2+, and two equivalent Fe3+ atoms to form distorted corner-sharing OBaSrFe2 tetrahedra. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, one Sr2+, and two Fe3+ atoms.