DOE OSTI2020
BaY2F8 crystallizes in the monoclinic Cm 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 2.76–2.99 Å. Y3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Y–F bond distances ranging from 2.27–2.35 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Ba2+ and two equivalent Y3+ atoms. In the second F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Ba2+ and two equivalent Y3+ atoms. In the third F1- site, F1- is bonded in a 3-coordinate geometry to one Ba2+ and two equivalent Y3+ atoms. In the fourth F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Ba2+ and two equivalent Y3+ atoms. In the fifth F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Ba2+ and two equivalent Y3+ atoms.