Materials Data on Li3Fe2(SiO4)2 by Materials Project
Li3Fe2(SiO4)2 is Clathrate-derived structured and crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are three 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 LiO4 tetrahedra, corners with two equivalent FeO4 tetrahedra, corners with four SiO4 tetrahedra, and an edgeedge with one LiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.92–2.23 Å. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 tetrahedra that share corners with four LiO4 tetrahedra, corners with four FeO4 tetrahedra, and corners with four SiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.95–2.44 Å. In the third Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with two equivalent LiO4 tetrahedra, corners with two equivalent FeO4 tetrahedra, corners with four SiO4 tetrahedra, and an edgeedge with one LiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.95–2.08 Å. There are two inequivalent Fe+2.50+ sites. In the first Fe+2.50+ site, Fe+2.50+ is bonded to four O2- atoms to form distorted FeO4 tetrahedra that share corners with four LiO4 tetrahedra, corners with four SiO4 tetrahedra, and an edgeedge with one FeO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.91–2.15 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 LiO4 tetrahedra, corners with four SiO4 tetrahedra, and an edgeedge with one FeO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.86–1.96 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 corners with four FeO4 tetrahedra and corners with six LiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.72 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four FeO4 tetrahedra and corners with six LiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.58–1.70 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to three Li1+ and one Si4+ atom to form OLi3Si tetrahedra that share corners with four OLi2FeSi tetrahedra and corners with two equivalent OLiFe2Si trigonal pyramids. In the second O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Fe+2.50+, and one Si4+ atom. 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 to one Li1+, two Fe+2.50+, and one Si4+ atom to form distorted corner-sharing OLiFe2Si trigonal pyramids. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Fe+2.50+ and one Si4+ atom. In the sixth O2- site, O2- is bonded to two Li1+, one Fe+2.50+, and one Si4+ atom to form OLi2FeSi tetrahedra that share corners with four OLi3Si tetrahedra and corners with two equivalent OLiFe2Si trigonal pyramids. In the seventh O2- site, O2- is bonded to two Li1+, one Fe+2.50+, and one Si4+ atom to form OLi2FeSi tetrahedra that share corners with four OLi3Si tetrahedra and corners with two equivalent OLiFe2Si trigonal pyramids. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Li1+ and one Si4+ atom.