Materials Data on Ba4NbFeO8 by Materials Project
Ba4NbFeO8 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to six O2- atoms to form distorted BaO6 pentagonal pyramids that share corners with three equivalent NbO6 octahedra and corners with three equivalent FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 9–16°. There are a spread of Ba–O bond distances ranging from 2.56–2.84 Å. In the second Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.60–3.18 Å. In the third Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.56–3.07 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.77–3.36 Å. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with three equivalent BaO6 pentagonal pyramids, and a cornercorner with one FeO4 tetrahedra. The corner-sharing octahedral tilt angles are 5°. There are a spread of Nb–O bond distances ranging from 1.92–2.25 Å. Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share a cornercorner with one NbO6 octahedra and corners with three equivalent BaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 11°. There are a spread of Fe–O bond distances ranging from 1.88–1.97 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to five Ba2+ and one Nb5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to five Ba2+ and one Nb5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+, one Nb5+, and one Fe3+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Ba2+ and one Fe3+ atom. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to four Ba2+ and one Fe3+ atom. In the sixth O2- site, O2- is bonded in a distorted tetrahedral geometry to three Ba2+ and one Fe3+ atom. In the seventh O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+ and two equivalent Nb5+ atoms. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to five Ba2+ and one Nb5+ atom.