Materials Data on Ca2Nd2Nb3FeO14 by Materials Project
Ca2Nd2Nb3FeO14 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to eight O2- atoms to form distorted CaO8 hexagonal bipyramids that share edges with two equivalent CaO8 hexagonal bipyramids, edges with four NdO8 hexagonal bipyramids, and edges with six NbO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.25–2.69 Å. In the second Ca2+ site, Ca2+ is bonded to eight O2- atoms to form distorted CaO8 hexagonal bipyramids that share edges with two equivalent CaO8 hexagonal bipyramids, edges with four NdO8 hexagonal bipyramids, edges with two equivalent FeO6 octahedra, and edges with four NbO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.28–2.69 Å. There are two inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded to eight O2- atoms to form distorted NdO8 hexagonal bipyramids that share edges with two equivalent NdO8 hexagonal bipyramids, edges with four CaO8 hexagonal bipyramids, edges with two equivalent FeO6 octahedra, and edges with four NbO6 octahedra. There are a spread of Nd–O bond distances ranging from 2.31–2.64 Å. In the second Nd3+ site, Nd3+ is bonded to eight O2- atoms to form distorted NdO8 hexagonal bipyramids that share edges with two equivalent NdO8 hexagonal bipyramids, edges with four CaO8 hexagonal bipyramids, edges with two equivalent FeO6 octahedra, and edges with four NbO6 octahedra. There are a spread of Nd–O bond distances ranging from 2.30–2.62 Å. There are three inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four NbO6 octahedra, edges with two equivalent NdO8 hexagonal bipyramids, and edges with four CaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 43–45°. There are a spread of Nb–O bond distances ranging from 2.00–2.03 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four NbO6 octahedra, edges with two equivalent NdO8 hexagonal bipyramids, and edges with four CaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 43–45°. There are a spread of Nb–O bond distances ranging from 1.95–2.06 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four NbO6 octahedra, edges with two equivalent CaO8 hexagonal bipyramids, and edges with four NdO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 44–47°. There are a spread of Nb–O bond distances ranging from 1.96–2.05 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six NbO6 octahedra, edges with two equivalent CaO8 hexagonal bipyramids, and edges with four NdO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 45–47°. There are a spread of Fe–O bond distances ranging from 2.01–2.05 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Nb5+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, one Nd3+, and two Nb5+ atoms. In the third O2- site, O2- is bonded to two Ca2+ and two Nd3+ atoms to form corner-sharing OCa2Nd2 tetrahedra. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, one Nd3+, one Nb5+, and one Fe3+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Nd3+, one Nb5+, and one Fe3+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, one Nd3+, one Nb5+, and one Fe3+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, one Nd3+, and two Nb5+ atoms.