Materials Data on KNa2AlH6 by Materials Project

Abstract

KNa2AlH6 crystallizes in the monoclinic P2_1 space group. The structure is two-dimensional and consists of one KNa2AlH6 sheet oriented in the (-1, 0, 1) direction. K1+ is bonded in a 4-coordinate geometry to four H1- atoms. There are a spread of K–H bond distances ranging from 2.58–2.88 Å. There are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a distorted T-shaped geometry to three H1- atoms. There are a spread of Na–H bond distances ranging from 2.15–2.43 Å. In the second Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three H1- atoms. There are a spread of Na–H bond distances ranging from 2.14–2.32 Å. Al3+ is bonded in a water-like geometry to two H1- atoms. Both Al–H bond lengths are 1.68 Å. There are six inequivalent H1- sites. In the first H1- site, H1- is bonded in a distorted water-like geometry to one K1+ and one H1- atom. The H–H bond length is 0.76 Å. In the second H1- site, H1- is bonded in a trigonal planar geometry to two equivalent K1+ and one Al3+ atom. In the third H1- site, H1- is bonded in a single-bond geometry to one H1- atom. In the fourth H1- site, H1- is bonded in a water-like geometry to one Na1+ and one Al3+ atom. In the fifth H1- site, H1- is bonded in a 3-coordinate geometry to three Na1+ atoms. In the sixth H1- site, H1- is bonded in a distorted trigonal planar geometry to one K1+ and two Na1+ atoms.