Materials Data on Li2NbFe3O8 by Materials Project
Li2NbFe3O8 is Spinel-derived structured and crystallizes in the hexagonal P6_3mc 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 NbO6 octahedra and corners with nine equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 58–60°. There are three shorter (2.01 Å) and one longer (2.02 Å) Li–O bond lengths. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 tetrahedra that share corners with three equivalent NbO6 octahedra, corners with three equivalent FeO6 octahedra, and edges with three equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 59–64°. There is one shorter (1.83 Å) and three longer (2.01 Å) Li–O bond length. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six equivalent FeO6 octahedra, corners with six LiO4 tetrahedra, and edges with three equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are three shorter (1.97 Å) and three longer (2.13 Å) Nb–O bond lengths. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four LiO4 tetrahedra, an edgeedge with one NbO6 octahedra, edges with four equivalent FeO6 octahedra, and an edgeedge with one LiO4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Fe–O bond distances ranging from 1.97–2.15 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Nb5+, and two equivalent Fe3+ atoms. In the second O2- site, O2- is bonded to one Li1+, one Nb5+, and two equivalent Fe3+ atoms to form distorted OLiNbFe2 tetrahedra that share corners with four OLiNbFe2 tetrahedra, a cornercorner with one OLiFe3 trigonal pyramid, edges with two equivalent OLiNbFe2 tetrahedra, and an edgeedge with one OLiFe3 trigonal pyramid. In the third O2- site, O2- is bonded to one Li1+ and three equivalent Fe3+ atoms to form a mixture of distorted edge and corner-sharing OLiFe3 trigonal pyramids. In the fourth O2- site, O2- is bonded to one Li1+ and three equivalent Fe3+ atoms to form OLiFe3 tetrahedra that share corners with six equivalent OLiNbFe2 tetrahedra and corners with three equivalent OLiFe3 trigonal pyramids.