Materials Data on BaFe2(PO4)2 by Materials Project

Abstract

BaFe2(PO4)2 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with six equivalent FeO6 octahedra, edges with six equivalent BaO12 cuboctahedra, edges with six equivalent PO4 tetrahedra, and faces with two equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are six shorter (2.92 Å) and six longer (3.18 Å) Ba–O bond lengths. Fe2+ is bonded to six equivalent O2- atoms to form FeO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with six equivalent PO4 tetrahedra, edges with three equivalent FeO6 octahedra, and a faceface with one BaO12 cuboctahedra. There are three shorter (2.13 Å) and three longer (2.16 Å) Fe–O bond lengths. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with six equivalent FeO6 octahedra and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 49–53°. There is one shorter (1.53 Å) and three longer (1.57 Å) P–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to three equivalent Ba2+ and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+, two equivalent Fe2+, and one P5+ atom.