Materials Data on Li2CoGe3O8 by Materials Project

Abstract

Li2CoGe3O8 is Spinel-derived structured and crystallizes in the cubic P2_13 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 three equivalent LiO6 octahedra and corners with nine equivalent GeO6 octahedra. The corner-sharing octahedra tilt angles range from 54–66°. All Li–O bond lengths are 1.97 Å. In the second Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with three equivalent LiO4 tetrahedra, corners with three equivalent CoO4 tetrahedra, and edges with six equivalent GeO6 octahedra. There are three shorter (2.12 Å) and three longer (2.13 Å) Li–O bond lengths. Co2+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with three equivalent LiO6 octahedra and corners with nine equivalent GeO6 octahedra. The corner-sharing octahedra tilt angles range from 57–66°. There is three shorter (1.98 Å) and one longer (2.01 Å) Co–O bond length. Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with three equivalent LiO4 tetrahedra, corners with three equivalent CoO4 tetrahedra, edges with two equivalent LiO6 octahedra, and edges with four equivalent GeO6 octahedra. There are a spread of Ge–O bond distances ranging from 1.86–2.01 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Li1+, one Co2+, and two equivalent Ge4+ atoms to form distorted OLiCoGe2 trigonal pyramids that share a cornercorner with one OCoGe3 tetrahedra, corners with nine OLiCoGe2 trigonal pyramids, an edgeedge with one OCoGe3 tetrahedra, and edges with two equivalent OLiCoGe2 trigonal pyramids. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three equivalent Ge4+ atoms. In the third O2- site, O2- is bonded to two Li1+ and two equivalent Ge4+ atoms to form distorted OLi2Ge2 trigonal pyramids that share corners with two equivalent OCoGe3 tetrahedra, corners with nine OLiCoGe2 trigonal pyramids, and edges with two equivalent OLi2Ge2 trigonal pyramids. In the fourth O2- site, O2- is bonded to one Co2+ and three equivalent Ge4+ atoms to form a mixture of distorted edge and corner-sharing OCoGe3 tetrahedra.