DOI: 10.17188/1699819
title: Materials Data on Na2Fe3(PO4)3 by Materials Project

description: Na2Fe3(PO4)3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with four FeO6 pentagonal pyramids, corners with two PO4 tetrahedra, an edgeedge with one NaO6 octahedra, edges with two FeO6 pentagonal pyramids, and edges with two PO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.32–2.52 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with four FeO6 pentagonal pyramids, corners with two PO4 tetrahedra, an edgeedge with one NaO6 octahedra, edges with two FeO6 pentagonal pyramids, and edges with two PO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.27–2.41 Å. There are three inequivalent Fe+2.33+ sites. In the first Fe+2.33+ site, Fe+2.33+ is bonded to six O2- atoms to form distorted FeO6 pentagonal pyramids that share corners with two equivalent NaO6 octahedra, corners with four FeO6 pentagonal pyramids, corners with four PO4 tetrahedra, edges with two NaO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 69–85°. There are a spread of Fe–O bond distances ranging from 2.03–2.47 Å. In the second Fe+2.33+ site, Fe+2.33+ is bonded to six O2- atoms to form distorted FeO6 pentagonal pyramids that share corners with four NaO6 octahedra, corners with four FeO6 pentagonal pyramids, corners with four PO4 tetrahedra, an edgeedge with one NaO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 60–70°. There are a spread of Fe–O bond distances ranging from 2.12–2.38 Å. In the third Fe+2.33+ site, Fe+2.33+ is bonded to six O2- atoms to form distorted FeO6 pentagonal pyramids that share corners with two equivalent NaO6 octahedra, corners with four FeO6 pentagonal pyramids, corners with four PO4 tetrahedra, an edgeedge with one NaO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 63–70°. There are a spread of Fe–O bond distances ranging from 1.97–2.18 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 two NaO6 octahedra, corners with four FeO6 pentagonal pyramids, edges with two NaO6 octahedra, and an edgeedge with one FeO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 57–61°. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with four FeO6 pentagonal pyramids, an edgeedge with one NaO6 octahedra, and an edgeedge with one FeO6 pentagonal pyramid. The corner-sharing octahedral tilt angles are 64°. There are a spread of P–O bond distances ranging from 1.54–1.59 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with four FeO6 pentagonal pyramids, an edgeedge with one NaO6 octahedra, and an edgeedge with one FeO6 pentagonal pyramid. The corner-sharing octahedral tilt angles are 58°. 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 distorted rectangular see-saw-like geometry to two Na1+, one Fe+2.33+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two equivalent Fe+2.33+, and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Fe+2.33+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two Fe+2.33+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Fe+2.33+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Fe+2.33+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Fe+2.33+, and one P5+ atom. In the eighth O2- site, O2- is bonded to one Na1+, two equivalent Fe+2.33+, and one P5+ atom to form distorted corner-sharing ONaFe2P trigonal pyramids. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to two Fe+2.33+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Fe+2.33+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+, one Fe+2.33+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Fe+2.33+, and one P5+ atom.