DOE OSTI2020
Li2FeCPO7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.98–2.19 Å. In the second Li1+ site, Li1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.97–2.20 Å. In the third 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 1.93–2.40 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 1.94–2.35 Å. In the fifth 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, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 64–77°. There are a spread of Li–O bond distances ranging from 1.95–2.36 Å. In the sixth 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, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 64–75°. There are a spread of Li–O bond distances ranging from 1.95–2.26 Å. In the seventh Li1+ site, Li1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.98–2.18 Å. In the eighth Li1+ site, Li1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.97–2.27 Å. There are four inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four PO4 tetrahedra and a cornercorner with one LiO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 2.00–2.17 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four PO4 tetrahedra and a cornercorner with one LiO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.99–2.17 Å. In the third Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four PO4 tetrahedra, a cornercorner with one LiO5 trigonal bipyramid, and an edgeedge with one LiO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.98–2.17 Å. In the fourth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four PO4 tetrahedra, a cornercorner with one LiO5 trigonal bipyramid, and an edgeedge with one LiO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.98–2.17 Å. There are four 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 1.27–1.32 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 1.27–1.32 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. In the fourth C4+ site, C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.27 Å) and two longer (1.32 Å) C–O bond length. 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 four FeO6 octahedra and a cornercorner with one LiO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 36–49°. 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 and a cornercorner with one LiO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 37–49°. There are a spread of P–O bond distances ranging from 1.54–1.56 Å. 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 LiO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 36–51°. There is two shorter (1.54 Å) and two longer (1.56 Å) P–O bond length. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four FeO6 octahedra and corners with two LiO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 38–50°. There are a spread of P–O bond distances ranging from 1.54–1.56 Å. There are twenty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, one Fe3+, and one C4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Li1+ and one C4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, one Fe3+, and one C4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one Fe3+, and one C4+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Li1+ and one C4+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one Fe3+, and one C4+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Li1+, one Fe3+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe3+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Fe3+, 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 distorted trigonal non-coplanar geometry to one Li1+, one Fe3+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Fe3+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Fe3+, and one P5+ atom. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one P5+ atom. In the twentieth O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe3+, and one P5+ atom. In the twenty-first O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one P5+ atom. In the twenty-second O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe3+, and one P5+ atom. In the twenty-third O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one Fe3+, and one C4+ atom. In the twenty-fourth O2- site, O2- is bonded in a trigonal non-coplanar geometry to two Li1+ and one C4+ atom. In the twenty-fifth O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one Fe3+, and one C4+ atom. In the twenty-sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one C4+ atom. In the twenty-seventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Li1+ and one C4+ atom. In the twenty-eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe3+, and one C4+ atom.