Materials Data on Li2BF5 by Materials Project
Li2BF5 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. Li1+ is bonded to six F1- atoms to form LiF6 octahedra that share corners with four equivalent LiF6 octahedra, corners with four equivalent BF4 tetrahedra, and faces with two equivalent LiF6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are two shorter (2.00 Å) and four longer (2.09 Å) Li–F bond lengths. B3+ is bonded to four equivalent F1- atoms to form BF4 tetrahedra that share corners with eight equivalent LiF6 octahedra. The corner-sharing octahedral tilt angles are 40°. All B–F bond lengths are 1.42 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 4-coordinate geometry to four equivalent Li1+ atoms. In the second F1- site, F1- is bonded in a 1-coordinate geometry to two equivalent Li1+ and one B3+ atom.