Materials Data on CaCr2F10 by Materials Project

Abstract

CaCr2F10 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Ca2+ is bonded to seven F1- atoms to form CaF7 pentagonal bipyramids that share corners with four equivalent CrF6 octahedra and edges with two equivalent CrF6 octahedra. The corner-sharing octahedra tilt angles range from 2–30°. There are a spread of Ca–F bond distances ranging from 2.26–2.53 Å. Cr4+ is bonded to six F1- atoms to form CrF6 octahedra that share corners with two equivalent CrF6 octahedra, corners with two equivalent CaF7 pentagonal bipyramids, and an edgeedge with one CaF7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 25–28°. There are a spread of Cr–F bond distances ranging from 1.76–1.98 Å. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Cr4+ atom. In the second F1- site, F1- is bonded in a linear geometry to one Ca2+ and one Cr4+ atom. In the third F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent Cr4+ atoms. In the fourth F1- site, F1- is bonded in a 2-coordinate geometry to one Ca2+ and two equivalent Cr4+ atoms. In the fifth F1- site, F1- is bonded in a bent 150 degrees geometry to one Ca2+ and one Cr4+ atom. In the sixth F1- site, F1- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and one Cr4+ atom.