Materials Data on CaAl2F10 by Materials Project
CaAl2F10 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Ca is bonded to seven F atoms to form distorted CaF7 pentagonal bipyramids that share corners with four equivalent AlF6 octahedra and edges with two equivalent AlF6 octahedra. The corner-sharing octahedra tilt angles range from 7–33°. There are a spread of Ca–F bond distances ranging from 2.25–2.63 Å. Al is bonded to six F atoms to form AlF6 octahedra that share corners with two equivalent AlF6 octahedra, corners with two equivalent CaF7 pentagonal bipyramids, and an edgeedge with one CaF7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 16–32°. There are a spread of Al–F bond distances ranging from 1.73–1.90 Å. There are six inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one Al atom. In the second F site, F is bonded in a linear geometry to one Ca and one Al atom. In the third F site, F is bonded in a distorted bent 150 degrees geometry to one Ca and two equivalent Al atoms. In the fourth F site, F is bonded in a linear geometry to two equivalent Al atoms. In the fifth F site, F is bonded in a bent 120 degrees geometry to one Ca and one Al atom. In the sixth F site, F is bonded in a bent 150 degrees geometry to one Ca and one Al atom.