Materials Data on KNa(BH4)2 by Materials Project

Abstract

NaK(BH4)2 crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. K1+ is bonded in a 12-coordinate geometry to twelve H+0.50+ atoms. There are a spread of K–H bond distances ranging from 2.72–2.92 Å. Na1+ is bonded in a 9-coordinate geometry to nine H+0.50+ atoms. There are three shorter (2.45 Å) and six longer (2.48 Å) Na–H bond lengths. There are two inequivalent B3- sites. In the first B3- site, B3- is bonded in a tetrahedral geometry to four H+0.50+ atoms. All B–H bond lengths are 1.23 Å. In the second B3- site, B3- is bonded in a tetrahedral geometry to four H+0.50+ atoms. There is one shorter (1.22 Å) and three longer (1.23 Å) B–H bond length. There are four inequivalent H+0.50+ sites. In the first H+0.50+ site, H+0.50+ is bonded in a single-bond geometry to three equivalent K1+ and one B3- atom. In the second H+0.50+ site, H+0.50+ is bonded in a single-bond geometry to three equivalent K1+ and one B3- atom. In the third H+0.50+ site, H+0.50+ is bonded in a distorted single-bond geometry to two equivalent Na1+ and one B3- atom. In the fourth H+0.50+ site, H+0.50+ is bonded in a distorted single-bond geometry to two equivalent K1+, one Na1+, and one B3- atom.