Materials Data on CsHf2Br9 by Materials Project
CsHf2Br9 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. Cs1+ is bonded to twelve Br1- atoms to form CsBr12 cuboctahedra that share corners with four equivalent HfBr6 octahedra, edges with four equivalent CsBr12 cuboctahedra, edges with two equivalent HfBr6 octahedra, and faces with two equivalent HfBr6 octahedra. The corner-sharing octahedra tilt angles range from 9–41°. There are a spread of Cs–Br bond distances ranging from 3.89–4.22 Å. Hf4+ is bonded to six Br1- atoms to form HfBr6 octahedra that share corners with two equivalent CsBr12 cuboctahedra, an edgeedge with one CsBr12 cuboctahedra, a faceface with one CsBr12 cuboctahedra, and a faceface with one HfBr6 octahedra. There are a spread of Hf–Br bond distances ranging from 2.51–2.78 Å. There are five inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a distorted single-bond geometry to one Cs1+ and one Hf4+ atom. In the second Br1- site, Br1- is bonded in a single-bond geometry to two equivalent Cs1+ and one Hf4+ atom. In the third Br1- site, Br1- is bonded in an L-shaped geometry to two equivalent Hf4+ atoms. In the fourth Br1- site, Br1- is bonded in a distorted L-shaped geometry to one Cs1+ and two equivalent Hf4+ atoms. In the fifth Br1- site, Br1- is bonded in a single-bond geometry to two equivalent Cs1+ and one Hf4+ atom.