DOI: 10.17188/1672279
title: Materials Data on Na2LiFePCO7 by Materials Project

description: Na2LiFeCPO7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four 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 2.28–2.70 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 equivalent NaO7 pentagonal bipyramids, corners with two PO4 tetrahedra, an edgeedge with one FeO6 octahedra, an edgeedge with one PO4 tetrahedra, edges with two equivalent LiO5 trigonal bipyramids, and a faceface with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 71°. There are a spread of Na–O bond distances ranging from 2.36–2.80 Å. In the third 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 2.30–2.82 Å. In the fourth 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 2.30–2.86 Å. There are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to five O2- atoms to form distorted LiO5 trigonal bipyramids that share corners with two FeO6 octahedra, corners with three PO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with two equivalent NaO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 65–87°. There are a spread of Li–O bond distances ranging from 2.13–2.53 Å. In the second Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 2.03–2.69 Å. There are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with four PO4 tetrahedra, a cornercorner with one LiO5 trigonal bipyramid, an edgeedge with one NaO7 pentagonal bipyramid, an edgeedge with one LiO5 trigonal bipyramid, and a faceface with one NaO7 pentagonal bipyramid. There are a spread of Fe–O bond distances ranging from 2.10–2.47 Å. In the second Fe2+ site, Fe2+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share a cornercorner with one NaO7 pentagonal bipyramid, corners with four PO4 tetrahedra, and a cornercorner with one LiO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 2.11–2.36 Å. There are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.30 Å) and one longer (1.31 Å) C–O bond length. In the second C4+ site, C4+ is bonded in a trigonal planar geometry to three O2- atoms. All C–O bond lengths are 1.30 Å. There are two 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, a cornercorner with one NaO7 pentagonal bipyramid, corners with two equivalent LiO5 trigonal bipyramids, and an edgeedge with one NaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 42–60°. 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 four FeO6 octahedra, a cornercorner with one NaO7 pentagonal bipyramid, and a cornercorner with one LiO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 42–57°. There are a spread of P–O bond distances ranging from 1.55–1.57 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Li1+, and one C4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Li1+, one Fe2+, and one C4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, two Li1+, one Fe2+, and one C4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+, one Fe2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Li1+, one Fe2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Li1+, one Fe2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Li1+, one Fe2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+, one Fe2+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe2+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Na1+, one Li1+, one Fe2+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Na1+, one Li1+, one Fe2+, and one P5+ atom. In the twelfth O2- site, O2- is bonded to three Na1+, one Fe2+, and one C4+ atom to form distorted corner-sharing ONa3FeC trigonal bipyramids. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+, one Fe2+, and one C4+ atom. In the fourteenth O2- site, O2- is bonded to two Na1+, one Li1+, and one C4+ atom to form distorted corner-sharing ONa2LiC tetrahedra.