Materials Data on LiFe2Si2O7 by Materials Project
LiFe2Si2O7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Li1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Li–O bond distances ranging from 1.92–2.02 Å. There are two inequivalent Fe+2.50+ sites. In the first Fe+2.50+ site, Fe+2.50+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Fe–O bond distances ranging from 2.00–2.48 Å. In the second Fe+2.50+ site, Fe+2.50+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.85–1.95 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with two equivalent FeO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with two equivalent FeO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Fe+2.50+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe+2.50+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Fe+2.50+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two Fe+2.50+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe+2.50+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Fe+2.50+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a trigonal non-coplanar geometry to two Fe+2.50+ and one Si4+ atom.