Materials Data on CaBiF5 by Materials Project

Abstract

CaBiF5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ca2+ is bonded to seven F1- atoms to form distorted CaF7 pentagonal bipyramids that share corners with four equivalent BiF6 octahedra, edges with two equivalent BiF6 octahedra, and edges with two equivalent CaF7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 12–45°. There are a spread of Ca–F bond distances ranging from 2.22–2.73 Å. Bi3+ is bonded to six F1- atoms to form BiF6 octahedra that share corners with two equivalent BiF6 octahedra, corners with four equivalent CaF7 pentagonal bipyramids, and edges with two equivalent CaF7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 50°. There are a spread of Bi–F bond distances ranging from 2.24–2.31 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one Bi3+ atom. In the second F1- site, F1- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one Bi3+ atom. In the third F1- site, F1- is bonded in a bent 150 degrees geometry to one Ca2+ and one Bi3+ atom. In the fourth F1- site, F1- is bonded in a linear geometry to one Ca2+ and one Bi3+ atom. In the fifth F1- site, F1- is bonded in a trigonal planar geometry to one Ca2+ and two equivalent Bi3+ atoms.