Materials Data on K2SrBe2F8 by Materials Project

Abstract

K2SrBe2F8 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. K1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.58–2.86 Å. Sr2+ is bonded in a 12-coordinate geometry to six equivalent F1- atoms. All Sr–F bond lengths are 2.55 Å. Be2+ is bonded in a tetrahedral geometry to four F1- atoms. There is one shorter (1.55 Å) and three longer (1.57 Å) Be–F bond length. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to three equivalent K1+, one Sr2+, and one Be2+ atom. In the second F1- site, F1- is bonded in a distorted single-bond geometry to one K1+ and one Be2+ atom.