Materials Data on Li6ZrBeF12 by Materials Project
Li6BeF4ZrF8 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six F1- atoms to form distorted LiF6 octahedra that share corners with four equivalent LiF6 octahedra, corners with two equivalent BeF4 tetrahedra, and edges with four equivalent LiF6 octahedra. The corner-sharing octahedral tilt angles are 60°. There are a spread of Li–F bond distances ranging from 1.94–2.16 Å. In the second Li1+ site, Li1+ is bonded to six F1- atoms to form distorted LiF6 octahedra that share corners with four LiF6 octahedra, corners with two equivalent BeF4 tetrahedra, and edges with four LiF6 octahedra. The corner-sharing octahedra tilt angles range from 51–60°. There are a spread of Li–F bond distances ranging from 1.85–2.32 Å. Be2+ is bonded to four equivalent F1- atoms to form BeF4 tetrahedra that share corners with twelve LiF6 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. All Be–F bond lengths are 1.59 Å. Zr4+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are four shorter (2.10 Å) and four longer (2.21 Å) Zr–F bond lengths. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a rectangular see-saw-like geometry to three Li1+ and one Be2+ atom. In the second F1- site, F1- is bonded to three Li1+ and one Zr4+ atom to form a mixture of distorted edge and corner-sharing FLi3Zr tetrahedra. In the third F1- site, F1- is bonded to three Li1+ and one Zr4+ atom to form a mixture of distorted edge and corner-sharing FLi3Zr trigonal pyramids.