Materials Data on Cs2HgF4 by Materials Project

Abstract

Cs2HgF4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Cs1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Cs–F bond distances ranging from 2.96–3.37 Å. Hg2+ is bonded to six F1- atoms to form corner-sharing HgF6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.27 Å) and four longer (2.38 Å) Hg–F bond lengths. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded to four equivalent Cs1+ and two equivalent Hg2+ atoms to form a mixture of corner, edge, and face-sharing FCs4Hg2 octahedra. The corner-sharing octahedra tilt angles range from 0–56°. In the second F1- site, F1- is bonded to five equivalent Cs1+ and one Hg2+ atom to form distorted FCs5Hg octahedra that share corners with seventeen FCs4Hg2 octahedra, edges with eight equivalent FCs5Hg octahedra, and faces with four equivalent FCs4Hg2 octahedra. The corner-sharing octahedra tilt angles range from 0–56°.