Materials Data on Mg(BH4)2 by Materials Project

Abstract

Mg(BH4)2 crystallizes in the orthorhombic Pmc2_1 space group. The structure is two-dimensional and consists of one Mg(BH4)2 sheet oriented in the (0, 1, 0) direction. Mg2+ is bonded in a 8-coordinate geometry to eight H+0.50+ atoms. There are a spread of Mg–H bond distances ranging from 1.99–2.21 Å. There are two inequivalent B3- sites. In the first B3- site, B3- is bonded in a tetrahedral geometry to four H+0.50+ atoms. There is two shorter (1.22 Å) and two longer (1.23 Å) B–H bond length. In the second B3- site, B3- is bonded in a tetrahedral geometry to four H+0.50+ atoms. There are a spread of B–H bond distances ranging from 1.20–1.24 Å. There are six inequivalent H+0.50+ sites. In the first H+0.50+ site, H+0.50+ is bonded in a water-like geometry to one Mg2+ and one B3- atom. In the second H+0.50+ site, H+0.50+ is bonded in a single-bond geometry to one B3- atom. In the third H+0.50+ site, H+0.50+ is bonded in an L-shaped geometry to one Mg2+ and one B3- atom. In the fourth H+0.50+ site, H+0.50+ is bonded in an L-shaped geometry to one Mg2+ and one B3- atom. In the fifth H+0.50+ site, H+0.50+ is bonded in an L-shaped geometry to one Mg2+ and one B3- atom. In the sixth H+0.50+ site, H+0.50+ is bonded in a distorted single-bond geometry to two equivalent Mg2+ and one B3- atom.