DOI: 10.17188/1754974
title: Materials Data on Na2FePCO7 by Materials Project

description: Na2FeCPO7 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are five inequivalent Na1+ sites. In the first 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 2.38–2.82 Å. In the second Na1+ site, Na1+ is bonded to seven O2- atoms to form distorted NaO7 pentagonal bipyramids that share a cornercorner with one FeO6 octahedra, corners with two PO4 tetrahedra, an edgeedge with one FeO6 octahedra, an edgeedge with one PO4 tetrahedra, a faceface with one FeO6 octahedra, and a faceface with one NaO7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 67°. There are a spread of Na–O bond distances ranging from 2.24–2.68 Å. In the third Na1+ site, Na1+ is bonded to seven O2- atoms to form distorted NaO7 pentagonal bipyramids that share a cornercorner with one FeO6 octahedra, corners with two PO4 tetrahedra, an edgeedge with one FeO6 octahedra, an edgeedge with one NaO7 pentagonal bipyramid, an edgeedge with one PO4 tetrahedra, and a faceface with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 65°. There are a spread of Na–O bond distances ranging from 2.31–2.73 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 2.32–2.83 Å. In the fifth 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 2.31–2.88 Å. There are three inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with two equivalent NaO7 pentagonal bipyramids, corners with four PO4 tetrahedra, and edges with two equivalent NaO7 pentagonal bipyramids. There are a spread of Fe–O bond distances ranging from 1.90–2.19 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with four PO4 tetrahedra and faces with two equivalent NaO7 pentagonal bipyramids. There are a spread of Fe–O bond distances ranging from 1.92–2.24 Å. In the third Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one NaO7 pentagonal bipyramid, corners with four PO4 tetrahedra, an edgeedge with one NaO7 pentagonal bipyramid, and a faceface with one NaO7 pentagonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.97–2.14 Å. There are three inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of C–O bond distances ranging from 1.26–1.33 Å. In the second C4+ site, C4+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of C–O bond distances ranging from 1.28–1.31 Å. In the third C4+ site, C4+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of C–O bond distances ranging from 1.27–1.32 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 four FeO6 octahedra, corners with two NaO7 pentagonal bipyramids, and an edgeedge with one NaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 33–44°. There are a spread of P–O bond distances ranging from 1.54–1.56 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four FeO6 octahedra, corners with two equivalent NaO7 pentagonal bipyramids, and edges with two equivalent NaO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 36–42°. There is three shorter (1.55 Å) and one longer (1.57 Å) P–O bond length. 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 NaO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 31–44°. There are a spread of P–O bond distances ranging from 1.54–1.56 Å. There are nineteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one C4+ atom. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Fe3+, and one C4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+, one Fe3+, and one C4+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to three Na1+, one Fe3+, and one C4+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one Fe3+, and one C4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe3+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe3+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na1+, one Fe3+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Fe3+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Fe3+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Fe3+, and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe3+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe3+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe3+, and one C4+ atom. In the seventeenth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe3+, and one C4+ atom. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and one C4+ atom. In the nineteenth O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one C4+ atom.