Materials Data on CsBa2Zn2F9 by Materials Project
CsBa2Zn2F9 crystallizes in the trigonal R3m space group. The structure is three-dimensional. Cs1+ is bonded to twelve F1- atoms to form distorted CsF12 cuboctahedra that share corners with six equivalent CsF12 cuboctahedra, corners with three equivalent ZnF6 octahedra, faces with four equivalent BaF12 cuboctahedra, and faces with four ZnF6 octahedra. The corner-sharing octahedral tilt angles are 27°. There are a spread of Cs–F bond distances ranging from 2.98–3.18 Å. There are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve F1- atoms to form BaF12 cuboctahedra that share corners with six equivalent BaF12 cuboctahedra, faces with four equivalent CsF12 cuboctahedra, and faces with six ZnF6 octahedra. There are a spread of Ba–F bond distances ranging from 2.78–3.00 Å. In the second Ba2+ site, Ba2+ is bonded in a 12-coordinate geometry to twelve F1- atoms. There are a spread of Ba–F bond distances ranging from 2.78–3.12 Å. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to six F1- atoms to form ZnF6 octahedra that share corners with three equivalent CsF12 cuboctahedra, corners with three equivalent ZnF6 octahedra, a faceface with one CsF12 cuboctahedra, and faces with three equivalent BaF12 cuboctahedra. The corner-sharing octahedral tilt angles are 7°. There are three shorter (1.99 Å) and three longer (2.16 Å) Zn–F bond lengths. In the second Zn2+ site, Zn2+ is bonded to six F1- atoms to form ZnF6 octahedra that share corners with three equivalent ZnF6 octahedra, faces with three equivalent CsF12 cuboctahedra, and faces with three equivalent BaF12 cuboctahedra. The corner-sharing octahedral tilt angles are 7°. There are three shorter (2.00 Å) and three longer (2.17 Å) Zn–F bond lengths. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to one Cs1+, three Ba2+, and one Zn2+ atom. In the second F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Cs1+, two Ba2+, and one Zn2+ atom. In the third F1- site, F1- is bonded in a distorted linear geometry to one Cs1+, three Ba2+, and two Zn2+ atoms.