Materials Data on Li3Fe2(CuO4)2 by Materials Project
Li3Fe2(CuO4)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent Li sites. In the first Li site, Li is bonded in a distorted square co-planar geometry to four O atoms. There are two shorter (2.09 Å) and two longer (2.10 Å) Li–O bond lengths. In the second Li site, Li is bonded to six O atoms to form LiO6 octahedra that share edges with two equivalent CuO6 octahedra and edges with four FeO6 octahedra. There are a spread of Li–O bond distances ranging from 2.15–2.19 Å. In the third Li site, Li is bonded in a square co-planar geometry to four O atoms. There are two shorter (2.01 Å) and two longer (2.02 Å) Li–O bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share edges with two equivalent LiO6 octahedra, edges with two equivalent FeO6 octahedra, and edges with two equivalent CuO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.89–2.22 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share edges with two equivalent LiO6 octahedra, edges with two equivalent FeO6 octahedra, and edges with two equivalent CuO6 octahedra. There are four shorter (1.99 Å) and two longer (2.16 Å) Fe–O bond lengths. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded in a distorted square co-planar geometry to four O atoms. There is two shorter (1.87 Å) and two longer (1.88 Å) Cu–O bond length. In the second Cu site, Cu is bonded to six O atoms to form distorted CuO6 octahedra that share edges with two equivalent LiO6 octahedra and edges with four FeO6 octahedra. There are four shorter (1.87 Å) and two longer (2.47 Å) Cu–O bond lengths. There are four inequivalent O sites. In the first O site, O is bonded to three Li and two Fe atoms to form distorted OLi3Fe2 square pyramids that share corners with five equivalent OLi3Fe2 square pyramids and edges with four equivalent OLi2Fe2Cu square pyramids. In the second O site, O is bonded to two Li, two Fe, and one Cu atom to form distorted OLi2Fe2Cu square pyramids that share corners with five equivalent OLi2Fe2Cu square pyramids and edges with four equivalent OLi3Fe2 square pyramids. In the third O site, O is bonded in a distorted rectangular see-saw-like geometry to one Li, one Fe, and two Cu atoms. In the fourth O site, O is bonded in a 4-coordinate geometry to one Li, one Fe, and two Cu atoms.