Materials Data on Li2Ta4O11 by Materials Project
Li2Ta4O11 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share corners with three equivalent TaO6 octahedra. The corner-sharing octahedra tilt angles range from 58–59°. There are a spread of Li–O bond distances ranging from 2.04–2.22 Å. There are three inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ta–O bond distances ranging from 1.98–2.47 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six equivalent LiO4 trigonal pyramids. All Ta–O bond lengths are 2.01 Å. In the third Ta5+ site, Ta5+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ta–O bond distances ranging from 1.98–2.49 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three Ta5+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+ and two Ta5+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+ and two Ta5+ atoms. In the fifth O2- site, O2- is bonded to one Li1+ and three Ta5+ atoms to form distorted corner-sharing OLiTa3 tetrahedra. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+ and two Ta5+ atoms.