DOE OSTI2020
Li3Fe(PO4)2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to five O2- atoms to form distorted LiO5 trigonal bipyramids that share a cornercorner with one FeO6 octahedra, corners with five PO4 tetrahedra, corners with two equivalent LiO5 trigonal bipyramids, corners with three equivalent LiO4 trigonal pyramids, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 63°. There are a spread of Li–O bond distances ranging from 2.05–2.43 Å. In the second Li1+ site, Li1+ is bonded to five O2- atoms to form distorted LiO5 trigonal bipyramids that share a cornercorner with one FeO6 octahedra, corners with five PO4 tetrahedra, corners with two equivalent LiO5 trigonal bipyramids, corners with three equivalent LiO4 trigonal pyramids, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 64°. There are a spread of Li–O bond distances ranging from 2.04–2.40 Å. In the third Li1+ site, Li1+ is bonded to five O2- atoms to form distorted LiO5 trigonal bipyramids that share a cornercorner with one FeO6 octahedra, corners with five PO4 tetrahedra, corners with two equivalent LiO5 trigonal bipyramids, corners with three equivalent LiO4 trigonal pyramids, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 64°. There are a spread of Li–O bond distances ranging from 2.05–2.39 Å. In the fourth Li1+ site, Li1+ is bonded to five O2- atoms to form distorted LiO5 trigonal bipyramids that share a cornercorner with one FeO6 octahedra, corners with five PO4 tetrahedra, corners with two equivalent LiO5 trigonal bipyramids, corners with three equivalent LiO4 trigonal pyramids, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 64°. There are a spread of Li–O bond distances ranging from 2.05–2.41 Å. In the fifth Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share corners with two FeO6 octahedra, corners with four PO4 tetrahedra, and corners with six LiO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 76°. There are a spread of Li–O bond distances ranging from 2.03–2.05 Å. In the sixth Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share corners with two FeO6 octahedra, corners with four PO4 tetrahedra, and corners with six LiO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 76°. There are a spread of Li–O bond distances ranging from 2.03–2.05 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six PO4 tetrahedra, corners with two LiO5 trigonal bipyramids, corners with two LiO4 trigonal pyramids, and edges with two LiO5 trigonal bipyramids. There are a spread of Fe–O bond distances ranging from 1.97–2.17 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six PO4 tetrahedra, corners with two LiO5 trigonal bipyramids, corners with two LiO4 trigonal pyramids, and edges with two LiO5 trigonal bipyramids. There are a spread of Fe–O bond distances ranging from 1.97–2.16 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 three equivalent FeO6 octahedra, corners with five LiO5 trigonal bipyramids, and corners with two equivalent LiO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 35–62°. 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 three equivalent FeO6 octahedra, corners with five LiO5 trigonal bipyramids, and corners with two equivalent LiO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 35–62°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent FeO6 octahedra, corners with five LiO5 trigonal bipyramids, and corners with two equivalent LiO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 35–62°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent FeO6 octahedra, corners with five LiO5 trigonal bipyramids, and corners with two equivalent LiO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 36–62°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded to two Li1+, one Fe3+, and one P5+ atom to form distorted corner-sharing OLi2FeP trigonal pyramids. In the second O2- site, O2- is bonded to two Li1+, one Fe3+, and one P5+ atom to form distorted corner-sharing OLi2FeP trigonal pyramids. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one P5+ atom. In the fifth O2- site, O2- is bonded to three Li1+ and one P5+ atom to form distorted corner-sharing OLi3P trigonal pyramids. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Fe3+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Fe3+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Fe3+, and one P5+ atom. In the tenth O2- site, O2- is bonded to three Li1+ and one P5+ atom to form distorted corner-sharing OLi3P trigonal pyramids. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Fe3+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded to two Li1+, one Fe3+, and one P5+ atom to form distorted corner-sharing OLi2FeP trigonal pyramids. In the sixteenth O2- site, O2- is bonded to two Li1+, one Fe3+, and one P5+ atom to form distorted corner-sharing OLi2FeP trigonal pyramids.