DOI: 10.17188/1285716
title: Materials Data on NaFe7(PO4)6 by Materials Project

description: NaFe7(PO4)6 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Na1+ is bonded in a distorted linear geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.79–3.11 Å. There are four inequivalent Fe+2.43+ sites. In the first Fe+2.43+ site, Fe+2.43+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Fe–O bond distances ranging from 1.89–2.12 Å. In the second Fe+2.43+ site, Fe+2.43+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with two PO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.88–1.99 Å. In the third Fe+2.43+ site, Fe+2.43+ is bonded to four O2- atoms to form distorted FeO4 trigonal pyramids that share corners with two PO4 tetrahedra and an edgeedge with one FeO4 trigonal pyramid. There are a spread of Fe–O bond distances ranging from 1.92–2.14 Å. In the fourth Fe+2.43+ site, Fe+2.43+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (1.95 Å) and two longer (2.23 Å) Fe–O bond lengths. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of P–O bond distances ranging from 1.58–1.76 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO4 tetrahedra and a cornercorner with one FeO4 trigonal pyramid. There are a spread of P–O bond distances ranging from 1.53–1.60 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO4 tetrahedra and a cornercorner with one FeO4 trigonal pyramid. There are a spread of P–O bond distances ranging from 1.53–1.56 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Fe+2.43+, and one P5+ atom. In the third O2- site, O2- is bonded in a trigonal non-coplanar geometry to two equivalent Fe+2.43+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Fe+2.43+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe+2.43+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Fe+2.43+ and one O2- atom. The O–O bond length is 1.52 Å. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe+2.43+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to two Fe+2.43+ and one O2- atom. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe+2.43+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe+2.43+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe+2.43+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, two Fe+2.43+, and one P5+ atom.