DOE OSTI2020
LiMnF4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Li–F bond distances ranging from 1.92–2.44 Å. In the second Li1+ site, Li1+ is bonded to five F1- atoms to form distorted LiF5 square pyramids that share corners with two equivalent LiF5 square pyramids and edges with three MnF6 octahedra. There are a spread of Li–F bond distances ranging from 1.98–2.42 Å. There are two inequivalent Mn3+ sites. In the first Mn3+ site, Mn3+ is bonded to six F1- atoms to form MnF6 octahedra that share corners with four MnF6 octahedra and edges with two equivalent LiF5 square pyramids. The corner-sharing octahedra tilt angles range from 0–13°. There are a spread of Mn–F bond distances ranging from 1.81–2.05 Å. In the second Mn3+ site, Mn3+ is bonded to six F1- atoms to form MnF6 octahedra that share corners with four MnF6 octahedra and an edgeedge with one LiF5 square pyramid. The corner-sharing octahedra tilt angles range from 0–15°. There are a spread of Mn–F bond distances ranging from 1.85–2.03 Å. There are nine inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted T-shaped geometry to one Li1+ and two equivalent Mn3+ atoms. In the second F1- site, F1- is bonded in a linear geometry to two Mn3+ atoms. In the third F1- site, F1- is bonded in a bent 120 degrees geometry to one Li1+ and one Mn3+ atom. In the fourth F1- site, F1- is bonded in a T-shaped geometry to one Li1+ and two equivalent Mn3+ atoms. In the fifth F1- site, F1- is bonded to three Li1+ and one Mn3+ atom to form a mixture of edge and corner-sharing FLi3Mn trigonal pyramids. In the sixth F1- site, F1- is bonded in a water-like geometry to one Li1+ and one Mn3+ atom. In the seventh F1- site, F1- is bonded to three Li1+ and one Mn3+ atom to form a mixture of distorted edge and corner-sharing FLi3Mn trigonal pyramids. In the eighth F1- site, F1- is bonded in a linear geometry to two equivalent Mn3+ atoms. In the ninth F1- site, F1- is bonded in a square co-planar geometry to two equivalent Li1+ and two equivalent Mn3+ atoms.