Materials Data on Rb2Hf3OF12 by Materials Project

Abstract

Rb2Hf3OF12 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to twelve F1- atoms to form face-sharing RbF12 cuboctahedra. There are six shorter (2.74 Å) and six longer (3.13 Å) Rb–F bond lengths. In the second Rb1+ site, Rb1+ is bonded to six equivalent F1- atoms to form distorted corner-sharing RbF6 cuboctahedra. The corner-sharing octahedral tilt angles are 74°. All Rb–F bond lengths are 2.82 Å. In the third Rb1+ site, Rb1+ is bonded to six F1- atoms to form distorted RbF6 octahedra that share corners with three equivalent RbF6 cuboctahedra and a faceface with one RbF12 cuboctahedra. There are three shorter (2.87 Å) and three longer (2.96 Å) Rb–F bond lengths. Hf4+ is bonded in a 8-coordinate geometry to one O2- and seven F1- atoms. The Hf–O bond length is 2.07 Å. There are a spread of Hf–F bond distances ranging from 1.99–2.20 Å. O2- is bonded in a distorted trigonal planar geometry to three equivalent Hf4+ atoms. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent Hf4+ atoms. In the second F1- site, F1- is bonded in a 2-coordinate geometry to two Rb1+ and two equivalent Hf4+ atoms. In the third F1- site, F1- is bonded in a distorted trigonal planar geometry to one Rb1+ and two equivalent Hf4+ atoms. In the fourth F1- site, F1- is bonded in a distorted single-bond geometry to two Rb1+ and one Hf4+ atom.