Materials Data on Na3FeP8O23 by Materials Project

Abstract

Na3FeP8O23 crystallizes in the cubic P4_132 space group. The structure is three-dimensional. Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six PO4 tetrahedra and edges with four equivalent NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.40–2.59 Å. Fe3+ is bonded to six equivalent O2- atoms to form FeO6 octahedra that share corners with six equivalent PO4 tetrahedra. All Fe–O bond lengths are 2.01 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent NaO6 octahedra and corners with three equivalent PO4 tetrahedra. The corner-sharing octahedral tilt angles are 58°. There is one shorter (1.48 Å) and three longer (1.58 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with two equivalent NaO6 octahedra, and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–60°. There are a spread of P–O bond distances ranging from 1.49–1.64 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent P5+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Na1+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Na1+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe3+ and one P5+ atom.