Materials Data on K2Be3Co2F12 by Materials Project

Abstract

K2Be3Co2F12 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.88–3.32 Å. In the second K1+ site, K1+ is bonded in a 12-coordinate geometry to twelve F1- atoms. There are a spread of K–F bond distances ranging from 2.95–3.27 Å. Be2+ is bonded to four F1- atoms to form BeF4 tetrahedra that share corners with four CoF6 octahedra. The corner-sharing octahedra tilt angles range from 16–47°. There are a spread of Be–F bond distances ranging from 1.55–1.58 Å. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six F1- atoms to form CoF6 octahedra that share corners with six equivalent BeF4 tetrahedra. There are three shorter (2.06 Å) and three longer (2.07 Å) Co–F bond lengths. In the second Co2+ site, Co2+ is bonded to six F1- atoms to form CoF6 octahedra that share corners with six equivalent BeF4 tetrahedra. There are three shorter (2.07 Å) and three longer (2.08 Å) Co–F bond lengths. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to one K1+, one Be2+, and one Co2+ atom. In the second F1- site, F1- is bonded in a distorted bent 150 degrees geometry to three K1+, one Be2+, and one Co2+ atom. In the third F1- site, F1- is bonded in a 2-coordinate geometry to two K1+, one Be2+, and one Co2+ atom. In the fourth F1- site, F1- is bonded in a 1-coordinate geometry to one K1+, one Be2+, and one Co2+ atom.