Materials Data on BaNb2Fe2(PO4)6 by Materials Project

Abstract

BaNb2Fe2(PO4)6 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ba2+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are two shorter (2.72 Å) and four longer (2.76 Å) Ba–O bond lengths. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Nb–O bond distances ranging from 1.96–2.03 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.96–2.09 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one NbO6 octahedra and corners with three equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 27–33°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent NbO6 octahedra and corners with two equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 23–33°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra and corners with three equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 19–35°. There are a spread of P–O bond distances ranging from 1.51–1.56 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb5+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nb5+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Fe3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Fe3+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb5+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Fe3+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb5+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb5+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb5+ and one P5+ atom.