Materials Data on BaCaFe2Co2O7 by Materials Project
BaCaFe2Co2O7 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share corners with twelve BaO12 cuboctahedra, edges with five FeO4 tetrahedra, edges with seven CoO4 tetrahedra, and faces with four CaO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.97–3.44 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with twelve BaO12 cuboctahedra, edges with five CoO4 tetrahedra, edges with seven FeO4 tetrahedra, and faces with four CaO6 octahedra. There are a spread of Ba–O bond distances ranging from 3.04–3.30 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with five FeO4 tetrahedra, corners with seven CoO4 tetrahedra, and faces with four BaO12 cuboctahedra. There are a spread of Ca–O bond distances ranging from 2.28–2.42 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with five CoO4 tetrahedra, corners with seven FeO4 tetrahedra, and faces with four BaO12 cuboctahedra. There are a spread of Ca–O bond distances ranging from 2.26–2.41 Å. There are three inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent CaO6 octahedra, corners with two equivalent FeO4 tetrahedra, corners with four CoO4 tetrahedra, and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of Fe–O bond distances ranging from 1.84–1.94 Å. In the second Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent CaO6 octahedra, corners with two equivalent FeO4 tetrahedra, corners with four CoO4 tetrahedra, and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 53–58°. There are a spread of Fe–O bond distances ranging from 1.84–1.97 Å. In the third Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three CaO6 octahedra, corners with two equivalent CoO4 tetrahedra, corners with four FeO4 tetrahedra, and edges with three BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 55–62°. There are a spread of Fe–O bond distances ranging from 1.94–2.06 Å. There are three inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with three CaO6 octahedra, corners with two FeO4 tetrahedra, corners with four equivalent CoO4 tetrahedra, and edges with three BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 55–59°. There are a spread of Co–O bond distances ranging from 1.87–1.91 Å. In the second Co2+ site, Co2+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with three CaO6 octahedra, corners with two FeO4 tetrahedra, corners with four CoO4 tetrahedra, and edges with three BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 55–61°. There are a spread of Co–O bond distances ranging from 1.92–2.04 Å. In the third Co2+ site, Co2+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with three CaO6 octahedra, corners with six FeO4 tetrahedra, and edges with three BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 53–62°. There are a spread of Co–O bond distances ranging from 1.83–1.94 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ba2+, one Ca2+, one Fe3+, and one Co2+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ba2+, one Ca2+, one Fe3+, and one Co2+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ba2+, one Ca2+, one Fe3+, and one Co2+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ba2+, one Ca2+, and two Fe3+ atoms. In the fifth O2- site, O2- is bonded in a tetrahedral geometry to three Fe3+ and one Co2+ atom. In the sixth O2- site, O2- is bonded in a tetrahedral geometry to one Fe3+ and three Co2+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two Ba2+, one Ca2+, and two equivalent Co2+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ba2+, one Ca2+, and two Co2+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ba2+, one Ca2+, and two equivalent Fe3+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to two Ba2+, one Ca2+, one Fe3+, and one Co2+ atom.