DOE OSTI2020
LiCr2O4 is Spinel-like structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with twelve CrO6 octahedra. The corner-sharing octahedra tilt angles range from 58–62°. There are a spread of Li–O bond distances ranging from 1.97–2.01 Å. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share corners with six CrO6 octahedra and edges with three CrO6 octahedra. The corner-sharing octahedra tilt angles range from 60–66°. There are a spread of Li–O bond distances ranging from 1.76–1.98 Å. There are four inequivalent Cr+3.50+ sites. In the first Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with two equivalent CrO6 octahedra, corners with three equivalent LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, edges with five CrO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 49–51°. There are a spread of Cr–O bond distances ranging from 1.91–1.99 Å. In the second Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six CrO6 octahedra, corners with three equivalent LiO4 tetrahedra, corners with three equivalent LiO4 trigonal pyramids, and edges with three CrO6 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There are a spread of Cr–O bond distances ranging from 2.02–2.11 Å. In the third Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with two equivalent CrO6 octahedra, corners with three equivalent LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, edges with five CrO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedral tilt angles are 53°. There are a spread of Cr–O bond distances ranging from 1.97–2.05 Å. In the fourth Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with two equivalent CrO6 octahedra, corners with three equivalent LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, edges with five CrO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Cr–O bond distances ranging from 1.91–1.99 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr+3.50+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr+3.50+ atoms. In the third O2- site, O2- is bonded to one Li1+ and three Cr+3.50+ atoms to form a mixture of distorted corner and edge-sharing OLiCr3 tetrahedra. In the fourth O2- site, O2- is bonded to one Li1+ and three Cr+3.50+ atoms to form a mixture of distorted corner and edge-sharing OLiCr3 trigonal pyramids. In the fifth O2- site, O2- is bonded to one Li1+ and three Cr+3.50+ atoms to form distorted corner-sharing OLiCr3 tetrahedra. In the sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Cr+3.50+ atoms. In the seventh O2- site, O2- is bonded to one Li1+ and three Cr+3.50+ atoms to form a mixture of distorted corner and edge-sharing OLiCr3 tetrahedra. In the eighth O2- site, O2- is bonded to one Li1+ and three Cr+3.50+ atoms to form a mixture of distorted corner and edge-sharing OLiCr3 tetrahedra.