Materials Data on Cs3GeF7 by Materials Project
Cs3GeF7 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of Cs–F bond distances ranging from 3.04–3.27 Å. In the second Cs1+ site, Cs1+ is bonded to six F1- atoms to form CsF6 octahedra that share corners with four equivalent GeF6 octahedra and corners with six equivalent CsF6 octahedra. The corner-sharing octahedra tilt angles range from 0–68°. There are two shorter (3.17 Å) and four longer (3.26 Å) Cs–F bond lengths. Ge4+ is bonded to six F1- atoms to form GeF6 octahedra that share corners with four equivalent CsF6 octahedra. The corner-sharing octahedral tilt angles are 68°. All Ge–F bond lengths are 1.84 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded to six Cs1+ atoms to form corner-sharing FCs6 octahedra. The corner-sharing octahedra tilt angles range from 0–25°. In the second F1- site, F1- is bonded in a distorted single-bond geometry to three equivalent Cs1+ and one Ge4+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to four Cs1+ and one Ge4+ atom.