Materials Data on BaTm2F8 by Materials Project
BaTm2F8 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Ba2+ is bonded to twelve F1- atoms to form face-sharing BaF12 cuboctahedra. There are a spread of Ba–F bond distances ranging from 2.77–2.95 Å. Tm3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Tm–F bond distances ranging from 2.23–2.31 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to one Ba2+ and two equivalent Tm3+ atoms. In the second F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Ba2+ and two equivalent Tm3+ atoms. In the third F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Ba2+ and two equivalent Tm3+ atoms.