DOI: 10.17188/1701582
title: Materials Data on Na4Fe3P4O15 by Materials Project

description: Na4Fe3(PO4)2(P2O7) crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with six PO4 tetrahedra, edges with two equivalent NaO6 octahedra, and faces with two equivalent FeO6 octahedra. There are a spread of Na–O bond distances ranging from 2.35–2.61 Å. In the second Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.46–2.70 Å. In the third Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–2.78 Å. In the fourth Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.41–2.80 Å. There are three inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one FeO6 octahedra, corners with four PO4 tetrahedra, an edgeedge with one FeO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 72°. There are a spread of Fe–O bond distances ranging from 2.09–2.35 Å. In the second Fe2+ site, Fe2+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four PO4 tetrahedra, an edgeedge with one PO4 tetrahedra, and faces with two equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 55–63°. There are a spread of Fe–O bond distances ranging from 2.08–2.26 Å. In the third Fe2+ site, Fe2+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with three FeO6 octahedra, corners with six PO4 tetrahedra, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 55–72°. There are a spread of Fe–O bond distances ranging from 2.07–2.68 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four FeO6 octahedra and an edgeedge with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 41–56°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent NaO6 octahedra, corners with four FeO6 octahedra, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 38–55°. There are a spread of P–O bond distances ranging from 1.55–1.58 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent NaO6 octahedra, corners with three FeO6 octahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–72°. There are a spread of P–O bond distances ranging from 1.52–1.65 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent NaO6 octahedra, corners with three FeO6 octahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–59°. There are a spread of P–O bond distances ranging from 1.52–1.66 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Fe2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe2+, and one P5+ atom. In the third O2- site, O2- is bonded to two Na1+, one Fe2+, and one P5+ atom to form distorted corner-sharing ONa2FeP tetrahedra. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Fe2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Fe2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Fe2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe2+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two P5+ atoms. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Na1+, one Fe2+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Fe2+, and one P5+ atom. In the twelfth O2- site, O2- is bonded to two Na1+, one Fe2+, and one P5+ atom to form distorted corner-sharing ONa2FeP tetrahedra. In the thirteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na1+, one Fe2+, and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, two Fe2+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one P5+ atom.