DOI: 10.17188/1298842
title: Materials Data on Li21(FeO4)4 by Materials Project

description: Li21(FeO4)4 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are twelve inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share corners with two FeO4 tetrahedra, corners with eight LiO4 tetrahedra, an edgeedge with one FeO4 tetrahedra, edges with three LiO4 tetrahedra, and an edgeedge with one LiO4 trigonal pyramid. There are a spread of Li–O bond distances ranging from 1.90–2.12 Å. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share corners with two FeO4 tetrahedra, corners with ten LiO4 tetrahedra, an edgeedge with one FeO4 tetrahedra, edges with three LiO4 tetrahedra, and an edgeedge with one LiO4 trigonal pyramid. There are a spread of Li–O bond distances ranging from 1.97–2.15 Å. In the third Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 tetrahedra that share corners with four FeO4 tetrahedra, corners with five LiO4 tetrahedra, corners with two equivalent LiO4 trigonal pyramids, edges with three LiO4 tetrahedra, and edges with two LiO4 trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.93–2.15 Å. In the fourth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with two equivalent LiO4 tetrahedra, corners with four FeO4 tetrahedra, corners with four LiO4 trigonal pyramids, edges with three LiO4 tetrahedra, and edges with two equivalent LiO4 trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.93–2.08 Å. In the fifth Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 tetrahedra that share corners with four FeO4 tetrahedra, corners with five LiO4 tetrahedra, corners with two equivalent LiO4 trigonal pyramids, edges with three LiO4 tetrahedra, and edges with two LiO4 trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.85–2.10 Å. In the sixth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with two equivalent LiO4 tetrahedra, corners with four FeO4 tetrahedra, corners with four LiO4 trigonal pyramids, and edges with six LiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.91–2.00 Å. In the seventh Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 tetrahedra that share corners with two FeO4 tetrahedra, corners with six LiO4 tetrahedra, corners with six LiO4 trigonal pyramids, an edgeedge with one FeO4 tetrahedra, and edges with three LiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.99–2.09 Å. In the eighth Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share corners with two equivalent FeO4 tetrahedra, corners with eight LiO4 tetrahedra, an edgeedge with one FeO4 tetrahedra, edges with two equivalent LiO4 tetrahedra, and edges with two LiO4 trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.93–2.09 Å. In the ninth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with eight LiO4 tetrahedra, corners with four equivalent LiO4 trigonal pyramids, an edgeedge with one FeO4 tetrahedra, and edges with four LiO4 tetrahedra. There are two shorter (2.06 Å) and two longer (2.11 Å) Li–O bond lengths. In the tenth Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with ten LiO4 tetrahedra, an edgeedge with one FeO4 tetrahedra, edges with two equivalent LiO4 tetrahedra, and edges with two LiO4 trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.96–2.15 Å. In the eleventh Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with four LiO4 tetrahedra, corners with eight LiO4 trigonal pyramids, an edgeedge with one FeO4 tetrahedra, and edges with two equivalent LiO4 tetrahedra. There are two shorter (2.05 Å) and two longer (2.06 Å) Li–O bond lengths. In the twelfth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with eight LiO4 tetrahedra, corners with four equivalent LiO4 trigonal pyramids, an edgeedge with one FeO4 tetrahedra, and edges with two equivalent LiO4 tetrahedra. There are two shorter (2.02 Å) and two longer (2.07 Å) Li–O bond lengths. There are three inequivalent Fe+2.75+ sites. In the first Fe+2.75+ site, Fe+2.75+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with ten LiO4 tetrahedra, corners with four LiO4 trigonal pyramids, an edgeedge with one LiO4 tetrahedra, and edges with two equivalent LiO4 trigonal pyramids. All Fe–O bond lengths are 1.93 Å. In the second Fe+2.75+ site, Fe+2.75+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with ten LiO4 tetrahedra, corners with four LiO4 trigonal pyramids, and edges with four LiO4 tetrahedra. There are two shorter (1.99 Å) and two longer (2.06 Å) Fe–O bond lengths. In the third Fe+2.75+ site, Fe+2.75+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with thirteen LiO4 tetrahedra, corners with two equivalent LiO4 trigonal pyramids, an edgeedge with one LiO4 tetrahedra, and edges with two LiO4 trigonal pyramids. There are a spread of Fe–O bond distances ranging from 1.91–1.96 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to five Li1+ and one Fe+2.75+ atom to form distorted OLi5Fe octahedra that share corners with two OLi5Fe octahedra, corners with two equivalent OLi6Fe pentagonal bipyramids, corners with two OLi5Fe pentagonal pyramids, an edgeedge with one OLi5Fe octahedra, edges with two OLi6Fe pentagonal bipyramids, and edges with three OLi5Fe pentagonal pyramids. The corner-sharing octahedra tilt angles range from 64–67°. In the second O2- site, O2- is bonded to five Li1+ and one Fe+2.75+ atom to form distorted OLi5Fe octahedra that share corners with two OLi5Fe octahedra, corners with four OLi5Fe pentagonal pyramids, an edgeedge with one OLi5Fe octahedra, edges with two OLi6Fe pentagonal bipyramids, and edges with three OLi5Fe pentagonal pyramids. The corner-sharing octahedra tilt angles range from 61–67°. In the third O2- site, O2- is bonded to five Li1+ and one Fe+2.75+ atom to form distorted OLi5Fe pentagonal pyramids that share corners with three OLi5Fe octahedra, a cornercorner with one OLi6Fe pentagonal bipyramid, edges with two equivalent OLi5Fe octahedra, edges with three OLi6Fe pentagonal bipyramids, and edges with two OLi5Fe pentagonal pyramids. The corner-sharing octahedra tilt angles range from 39–64°. In the fourth O2- site, O2- is bonded to five Li1+ and one Fe+2.75+ atom to form distorted OLi5Fe octahedra that share a cornercorner with one OLi5Fe octahedra, a cornercorner with one OLi6Fe pentagonal bipyramid, corners with four OLi5Fe pentagonal pyramids, edges with two OLi5Fe octahedra, an edgeedge with one OLi6Fe pentagonal bipyramid, and edges with three OLi5Fe pentagonal pyramids. The corner-sharing octahedral tilt angles are 68°. In the fifth O2- site, O2- is bonded to six Li1+ and one Fe+2.75+ atom to form distorted OLi6Fe pentagonal bipyramids that share a cornercorner with one OLi5Fe octahedra, corners with two OLi5Fe pentagonal pyramids, edges with two OLi5Fe octahedra, edges with four OLi6Fe pentagonal bipyramids, and edges with three OLi5Fe pentagonal pyramids. The corner-sharing octahedral tilt angles are 57°. In the sixth O2- site, O2- is bonded to five Li1+ and one Fe+2.75+ atom to form distorted OLi5Fe pentagonal pyramids that share corners with three OLi5Fe octahedra, a cornercorner with one OLi6Fe pentagonal bipyramid, edges with four OLi5Fe octahedra, an edgeedge with one OLi6Fe pentagonal bipyramid, and edges with two OLi5Fe pentagonal pyramids. The corner-sharing octahedra tilt angles range from 49–63°. In the seventh O2- site, O2- is bonded to five Li1+ and one Fe+2.75+ atom to form distorted OLi5Fe pentagonal pyramids that share corners with four OLi5Fe octahedra, edges with three OLi5Fe octahedra, edges with two OLi6Fe pentagonal bipyramids, and edges with two OLi5Fe pentagonal pyramids. The corner-sharing octahedra tilt angles range from 42–60°. In the eighth O2- site, O2- is bonded to six Li1+ and one Fe+2.75+ atom to form distorted OLi6Fe pentagonal bipyramids that share corners with two equivalent OLi5Fe octahedra, a cornercorner with one OLi6Fe pentagonal bipyramid, edges with three OLi5Fe octahedra, edges with three equivalent OLi6Fe pentagonal bipyramids, and edges with three OLi5Fe pentagonal pyramids. The corner-sharing octahedra tilt angles range from 48–63°.