Materials Data on Li7Fe4(P2O7)4 by Materials Project
Li7Fe4(P2O7)4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are seven inequivalent Li1+ sites. In the first 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 1.96–2.35 Å. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 tetrahedra that share corners with four PO4 tetrahedra, a cornercorner with one FeO5 trigonal bipyramid, and an edgeedge with one FeO6 octahedra. There are a spread of Li–O bond distances ranging from 1.93–2.10 Å. In the third Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 tetrahedra that share corners with four PO4 tetrahedra, a cornercorner with one FeO5 trigonal bipyramid, and an edgeedge with one LiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.90–1.98 Å. In the fourth 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 1.96–2.58 Å. In the fifth 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 1.95–2.43 Å. In the sixth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with four PO4 tetrahedra, a cornercorner with one FeO5 trigonal bipyramid, and an edgeedge with one LiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.89–1.99 Å. In the seventh Li1+ site, Li1+ is bonded to five O2- atoms to form distorted LiO5 trigonal bipyramids that share corners with five PO4 tetrahedra, a cornercorner with one FeO5 trigonal bipyramid, an edgeedge with one FeO6 octahedra, and an edgeedge with one LiO5 trigonal bipyramid. There are a spread of Li–O bond distances ranging from 1.85–2.62 Å. There are four inequivalent Fe+2.25+ sites. In the first Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six PO4 tetrahedra, an edgeedge with one LiO5 trigonal bipyramid, and an edgeedge with one FeO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 2.14–2.22 Å. In the second Fe+2.25+ site, Fe+2.25+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share corners with two LiO4 tetrahedra, corners with five PO4 tetrahedra, and an edgeedge with one FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.08–2.24 Å. In the third Fe+2.25+ site, Fe+2.25+ is bonded to five O2- atoms to form distorted FeO5 trigonal bipyramids that share a cornercorner with one LiO4 tetrahedra, corners with five PO4 tetrahedra, a cornercorner with one LiO5 trigonal bipyramid, and an edgeedge with one FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.10–2.31 Å. In the fourth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six PO4 tetrahedra, an edgeedge with one LiO4 tetrahedra, and an edgeedge with one FeO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.96–2.14 Å. There are eight inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra, a cornercorner with one LiO4 tetrahedra, a cornercorner with one PO4 tetrahedra, and corners with two FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 50°. There are a spread of P–O bond distances ranging from 1.52–1.61 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra, a cornercorner with one PO4 tetrahedra, corners with two LiO4 tetrahedra, and a cornercorner with one FeO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 40°. There are a spread of P–O bond distances ranging from 1.51–1.63 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra, a cornercorner with one PO4 tetrahedra, corners with two equivalent LiO4 tetrahedra, a cornercorner with one LiO5 trigonal bipyramid, and corners with two FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 57°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three FeO6 octahedra, a cornercorner with one LiO4 tetrahedra, a cornercorner with one PO4 tetrahedra, and a cornercorner with one LiO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 26–57°. There are a spread of P–O bond distances ranging from 1.52–1.62 Å. In the fifth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three FeO6 octahedra, a cornercorner with one LiO4 tetrahedra, a cornercorner with one PO4 tetrahedra, and a cornercorner with one LiO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 32–47°. There are a spread of P–O bond distances ranging from 1.52–1.62 Å. In the sixth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra, a cornercorner with one PO4 tetrahedra, corners with three LiO4 tetrahedra, and corners with two FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 54°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. In the seventh P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra, a cornercorner with one PO4 tetrahedra, corners with two equivalent LiO5 trigonal bipyramids, and corners with two FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 55°. There are a spread of P–O bond distances ranging from 1.50–1.64 Å. In the eighth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra, a cornercorner with one PO4 tetrahedra, corners with two LiO4 tetrahedra, and a cornercorner with one FeO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 38°. There are a spread of P–O bond distances ranging from 1.51–1.60 Å. There are twenty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to two Li1+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Fe+2.25+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.25+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Fe+2.25+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe+2.25+, and one P5+ atom. In the seventh O2- site, O2- is bonded to two Li1+, one Fe+2.25+, and one P5+ atom to form distorted corner-sharing OLi2FeP tetrahedra. In the eighth O2- site, O2- is bonded in a trigonal planar geometry to two Li1+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P5+ atoms. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Li1+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Fe+2.25+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+, one Fe+2.25+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded to two Li1+, one Fe+2.25+, and one P5+ atom to form distorted corner-sharing OLi2FeP tetrahedra. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe+2.25+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe+2.25+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a trigonal non-coplanar geometry to one Li1+, one Fe+2.25+, and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Li1+, one Fe+2.25+, and one P5+ atom. In the eighteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Fe+2.25+, and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the twentieth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Li1+ and one P5+ atom. In the twenty-first O2- site, O2- is bonded in a trigonal planar geometry to two Li1+ and one P5+ atom. In the twenty-second O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe+2.25+, and one P5+ atom. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe+2.25+, and one P5+ atom. In the twenty-fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the twenty-fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.25+ and one P5+ atom. In the twenty-sixth O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Fe+2.25+, and one P5+ atom. In the twenty-seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe+2.25+ and one P5+ atom. In the twenty-eighth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Li1+ and one P5+ atom.