Materials Data on Na2FePO5 by Materials Project
Na2FePO5 crystallizes in the orthorhombic Pbcn space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first 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 2.38–2.97 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 2.31–2.82 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one FeO6 octahedra, corners with four equivalent PO4 tetrahedra, and a faceface with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Fe–O bond distances ranging from 1.89–2.18 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 32–53°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, two equivalent Fe3+, and one P5+ atom. In the second O2- site, O2- is bonded in an octahedral geometry to four Na1+ and two equivalent Fe3+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to four Na1+ and two equivalent Fe3+ atoms. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to four Na1+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+, one Fe3+, and one P5+ atom.