DOE OSTI2020
Li4(FeO2)9 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Li sites. In the first Li site, Li is bonded to five O atoms to form distorted LiO5 trigonal bipyramids that share corners with five FeO6 octahedra, edges with four FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 11–75°. There are a spread of Li–O bond distances ranging from 2.13–2.18 Å. In the second Li site, Li is bonded in a distorted pentagonal planar geometry to five O atoms. There are a spread of Li–O bond distances ranging from 2.19–2.26 Å. In the third Li site, Li is bonded in a distorted pentagonal planar geometry to five O atoms. There are a spread of Li–O bond distances ranging from 2.16–2.27 Å. In the fourth Li site, Li is bonded to five O atoms to form distorted LiO5 trigonal bipyramids that share corners with five FeO6 octahedra, edges with four FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 12–72°. There are a spread of Li–O bond distances ranging from 2.15–2.20 Å. In the fifth Li site, Li is bonded to five O atoms to form distorted LiO5 trigonal bipyramids that share corners with five FeO6 octahedra, edges with four FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 12–72°. There are a spread of Li–O bond distances ranging from 2.15–2.19 Å. In the sixth Li site, Li is bonded in a distorted pentagonal planar geometry to five O atoms. There are a spread of Li–O bond distances ranging from 2.17–2.25 Å. In the seventh Li site, Li is bonded in a distorted pentagonal planar geometry to five O atoms. There are a spread of Li–O bond distances ranging from 2.20–2.28 Å. In the eighth Li site, Li is bonded to five O atoms to form distorted LiO5 trigonal bipyramids that share corners with five FeO6 octahedra, edges with four FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 13–73°. There are a spread of Li–O bond distances ranging from 2.15–2.20 Å. There are eighteen inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two FeO6 octahedra, corners with four LiO5 trigonal bipyramids, edges with six FeO6 octahedra, and edges with two LiO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 9–10°. There are a spread of Fe–O bond distances ranging from 2.03–2.09 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three LiO5 trigonal bipyramids, edges with four FeO6 octahedra, and an edgeedge with one LiO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 51°. There are a spread of Fe–O bond distances ranging from 1.94–2.08 Å. In the third Fe site, Fe is bonded to six O atoms to form a mixture of distorted corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 10–54°. There are a spread of Fe–O bond distances ranging from 1.96–2.23 Å. In the fourth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, edges with six FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 52°. There are a spread of Fe–O bond distances ranging from 1.93–2.00 Å. In the fifth Fe site, Fe is bonded to six O atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 52–54°. There are a spread of Fe–O bond distances ranging from 1.98–2.07 Å. In the sixth Fe site, Fe is bonded to six O atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Fe–O bond distances ranging from 1.98–2.07 Å. In the seventh Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, edges with four FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 51°. There are a spread of Fe–O bond distances ranging from 1.92–2.00 Å. In the eighth Fe site, Fe is bonded to six O atoms to form a mixture of distorted corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 11–54°. There are a spread of Fe–O bond distances ranging from 1.97–2.26 Å. In the ninth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three LiO5 trigonal bipyramids, edges with four FeO6 octahedra, and an edgeedge with one LiO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 52°. There are a spread of Fe–O bond distances ranging from 1.93–2.07 Å. In the tenth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share a cornercorner with one FeO6 octahedra, corners with four LiO5 trigonal bipyramids, edges with six FeO6 octahedra, and edges with two LiO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 11°. There are a spread of Fe–O bond distances ranging from 2.03–2.10 Å. In the eleventh Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three LiO5 trigonal bipyramids, edges with four FeO6 octahedra, and an edgeedge with one LiO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 53°. There are a spread of Fe–O bond distances ranging from 1.91–2.06 Å. In the twelfth Fe site, Fe is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Fe–O bond distances ranging from 1.97–2.56 Å. In the thirteenth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, edges with six FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 53°. There are a spread of Fe–O bond distances ranging from 1.91–2.02 Å. In the fourteenth Fe site, Fe is bonded to six O atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Fe–O bond distances ranging from 1.97–2.08 Å. In the fifteenth Fe site, Fe is bonded to six O atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Fe–O bond distances ranging from 1.97–2.08 Å. In the sixteenth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, edges with six FeO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 53°. There are a spread of Fe–O bond distances ranging from 1.90–2.02 Å. In the seventeenth Fe site, Fe is bonded to six O atoms to form a mixture of distorted corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 9–54°. There are a spread of Fe–O bond distances ranging from 1.97–2.50 Å. In the eighteenth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three LiO5 trigonal bipyramids, edges with four FeO6 octahedra, and an edgeedge with one LiO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 53°. There are a spread of Fe–O bond distances ranging from 1.92–2.09 Å. There are thirty-six inequivalent O sites. In the first O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the second O site, O is bonded in a distorted rectangular see-saw-like geometry to four Fe atoms. In the third O site, O is bonded in a square co-planar geometry to two equivalent Li and two equivalent Fe atoms. In the fourth O site, O is bonded to two equivalent Li and three Fe atoms to form OLi2Fe3 trigonal bipyramids that share corners with four OLiFe3 tetrahedra and edges with two equivalent OLi2Fe3 trigonal bipyramids. In the fifth O site, O is bonded in a 5-coordinate geometry to two equivalent Li and three Fe atoms. In the sixth O site, O is bonded to one Li and three Fe atoms to form OLiFe3 tetrahedra that share corners with two equivalent OLiFe3 tetrahedra and corners with four OLi2Fe3 trigonal bipyramids. In the seventh O site, O is bonded to two equivalent Li and three Fe atoms to form a mixture of corner and edge-sharing OLi2Fe3 square pyramids. In the eighth O site, O is bonded in a trigonal planar geometry to three Fe atoms. In the ninth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Fe atoms. In the tenth O site, O is bonded in a rectangular see-saw-like geometry to one Li and three Fe atoms. In the eleventh O site, O is bonded in a rectangular see-saw-like geometry to one Li and three Fe atoms. In the twelfth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Fe atoms. In the thirteenth O site, O is bonded in a trigonal planar geometry to three Fe atoms. In the fourteenth O site, O is bonded to two equivalent Li and three Fe atoms to form a mixture of corner and edge-sharing OLi2Fe3 square pyramids. In the fifteenth O site, O is bonded to one Li and three Fe atoms to form OLiFe3 tetrahedra that share corners with two equivalent OLiFe3 tetrahedra and corners with four OLi2Fe3 trigonal bipyramids. In the sixteenth O site, O is bonded in a 5-coordinate geometry to two equivalent Li and three Fe atoms. In the seventeenth O site, O is bonded to two equivalent Li and three Fe atoms to form OLi2Fe3 trigonal bipyramids that share corners with four OLiFe3 tetrahedra and edges with two equivalent OLi2Fe3 trigonal bipyramids. In the eighteenth O site, O is bonded in a square co-planar geometry to two equivalent Li and two equivalent Fe atoms. In the nineteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to four Fe atoms. In the twentieth O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the twenty-first O site, O is bonded in a square co-planar geometry to two equivalent Li and two equivalent Fe atoms. In the twenty-second O site, O is bonded to two equivalent Li and three Fe atoms to form OLi2Fe3 trigonal bipyramids that share corners with four OLiFe3 tetrahedra, corners with two equivalent OLi2Fe3 trigonal bipyramids, and edges with three OLi2Fe3 trigonal bipyramids. In the twenty-third O site, O is bonded to two equivalent Li and three Fe atoms to form distorted OLi2Fe3 trigonal bipyramids that share a cornercorner with one OLi2Fe3 square pyramid, corners with two equivalent OLi2Fe3 trigonal bipyramids, edges with two equivalent OLiFe3 tetrahedra, and edges with three OLi2Fe3 trigonal bipyramids. In the twenty-fourth O site, O is bonded to one Li and three Fe atoms to form distorted OLiFe3 tetrahedra that share corners with two equivalent OLiFe3 tetrahedra, corners with four OLi2Fe3 trigonal bipyramids, and edges with two equivalent OLi2Fe3 trigonal bipyramids. In the twenty-fifth O site, O is bonded to two equivalent Li and three Fe atoms to form a mixture of corner and edge-sharing OLi2Fe3 square pyramids. In the twenty-sixth O site, O is bonded in a distorted trigonal planar geometry to three Fe atoms. In the twenty-seventh O site, O is bonded in a distorted trigonal non-coplanar geometry to three Fe atoms. In the twenty-eighth O site, O is bonded in a rectangular see-saw-like geometry to one Li and three Fe atoms. In the twenty-ninth O site, O is bonded in a rectangular see-saw-like geometry to one Li and three Fe atoms. In the thirtieth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Fe atoms. In the thirty-first O site, O is bonded in a distorted trigonal plan