Materials Data on K2Ba(FeAs)6 by Materials Project

Abstract

K2Ba(FeAs)6 is alpha bismuth trifluoride-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of K–As bond distances ranging from 3.32–3.45 Å. Ba2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Ba–As bond distances ranging from 3.38–3.41 Å. There are two inequivalent Fe+2.33+ sites. In the first Fe+2.33+ site, Fe+2.33+ is bonded to four As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.34 Å. In the second Fe+2.33+ site, Fe+2.33+ is bonded to four As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. There are two shorter (2.31 Å) and two longer (2.32 Å) Fe–As bond lengths. There are three inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to three equivalent K1+, one Ba2+, and four Fe+2.33+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to three equivalent K1+, one Ba2+, and four equivalent Fe+2.33+ atoms. In the third As3- site, As3- is bonded in a 8-coordinate geometry to two equivalent K1+, two equivalent Ba2+, and four Fe+2.33+ atoms.