Materials Data on Li2Mn2F7 by Materials Project
Li2Mn2F7 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Li1+ is bonded to five F1- atoms to form distorted LiF5 trigonal bipyramids that share corners with five equivalent MnF5 trigonal bipyramids, an edgeedge with one MnF5 trigonal bipyramid, and edges with two equivalent LiF5 trigonal bipyramids. There are a spread of Li–F bond distances ranging from 1.85–2.20 Å. Mn+2.50+ is bonded to five F1- atoms to form MnF5 trigonal bipyramids that share a cornercorner with one MnF5 trigonal bipyramid, corners with five equivalent LiF5 trigonal bipyramids, an edgeedge with one LiF5 trigonal bipyramid, and an edgeedge with one MnF5 trigonal bipyramid. There are a spread of Mn–F bond distances ranging from 1.92–2.14 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a bent 150 degrees geometry to one Li1+ and one Mn+2.50+ atom. In the second F1- site, F1- is bonded in a distorted T-shaped geometry to two equivalent Li1+ and one Mn+2.50+ atom. In the third F1- site, F1- is bonded to two equivalent Li1+ and two equivalent Mn+2.50+ atoms to form distorted edge-sharing FLi2Mn2 tetrahedra. In the fourth F1- site, F1- is bonded in a linear geometry to two equivalent Mn+2.50+ atoms.