Materials Data on LiY3Si2(O4F)2 by Materials Project

Abstract

LiY3(SiO4)2F2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Li1+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are two shorter (2.16 Å) and two longer (2.18 Å) Li–O bond lengths. There are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded in a 8-coordinate geometry to six O2- and two equivalent F1- atoms. There are a spread of Y–O bond distances ranging from 2.32–2.50 Å. Both Y–F bond lengths are 2.25 Å. In the second Y3+ site, Y3+ is bonded to six O2- and one F1- atom to form distorted YO6F pentagonal bipyramids that share corners with two equivalent YO6F pentagonal bipyramids, corners with four equivalent SiO4 tetrahedra, an edgeedge with one YO6F pentagonal bipyramid, and an edgeedge with one SiO4 tetrahedra. There are a spread of Y–O bond distances ranging from 2.29–2.49 Å. The Y–F bond length is 2.24 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent YO6F pentagonal bipyramids and an edgeedge with one YO6F pentagonal bipyramid. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Y3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, two Y3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, two Y3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Y3+ and one Si4+ atom. F1- is bonded in a distorted bent 150 degrees geometry to two Y3+ atoms.