Materials Data on NaFe7(PO4)6 by Materials Project

Abstract

NaFe7(PO4)6 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.48–2.99 Å. There are four inequivalent Fe+2.43+ sites. In the first Fe+2.43+ site, Fe+2.43+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with six PO4 tetrahedra, and corners with two equivalent FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 65°. There are a spread of Fe–O bond distances ranging from 2.09–2.31 Å. In the second Fe+2.43+ site, Fe+2.43+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share a cornercorner with one FeO6 octahedra, corners with five PO4 tetrahedra, and edges with two FeO6 octahedra. The corner-sharing octahedral tilt angles are 64°. There are a spread of Fe–O bond distances ranging from 2.03–2.16 Å. In the third Fe+2.43+ site, Fe+2.43+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six PO4 tetrahedra, an edgeedge with one FeO6 octahedra, and an edgeedge with one FeO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.93–2.17 Å. In the fourth Fe+2.43+ site, Fe+2.43+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one FeO6 octahedra, corners with six PO4 tetrahedra, an edgeedge with one FeO6 octahedra, and an edgeedge with one FeO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 65°. There are a spread of Fe–O bond distances ranging from 1.97–2.14 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 corners with five FeO6 octahedra and corners with two equivalent FeO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 36–59°. 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 six FeO6 octahedra and a cornercorner with one FeO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 26–54°. 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 corners with four FeO6 octahedra and corners with two equivalent FeO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 24–61°. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Fe+2.43+, and one P5+ atom. 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 distorted trigonal planar geometry to two Fe+2.43+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Fe+2.43+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Fe+2.43+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, two Fe+2.43+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.43+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe+2.43+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to two Fe+2.43+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Fe+2.43+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 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 two Fe+2.43+ and one P5+ atom.