Materials Data on Li2FeSiO4 by Materials Project

Abstract

Li2FeSiO4 is beta beryllia-derived structured and crystallizes in the orthorhombic C222_1 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 two equivalent SiO4 tetrahedra, corners with four equivalent LiO4 tetrahedra, corners with four equivalent FeO4 tetrahedra, and an edgeedge with one SiO4 tetrahedra. There are two shorter (1.99 Å) and two longer (2.09 Å) Li–O bond lengths. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with four equivalent LiO4 tetrahedra, corners with four equivalent SiO4 tetrahedra, and an edgeedge with one FeO4 tetrahedra. There are two shorter (1.95 Å) and two longer (2.07 Å) Li–O bond lengths. Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with four equivalent SiO4 tetrahedra, corners with six LiO4 tetrahedra, and an edgeedge with one LiO4 tetrahedra. There are two shorter (2.01 Å) and two longer (2.05 Å) Fe–O bond lengths. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent FeO4 tetrahedra, corners with six LiO4 tetrahedra, and an edgeedge with one LiO4 tetrahedra. All Si–O bond lengths are 1.66 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to two Li1+, one Fe2+, and one Si4+ atom to form a mixture of edge and corner-sharing OLi2FeSi tetrahedra. In the second O2- site, O2- is bonded to two Li1+, one Fe2+, and one Si4+ atom to form a mixture of distorted edge and corner-sharing OLi2FeSi trigonal pyramids.