Materials Data on Mg(BH4)2 by Materials Project

Abstract

Mg(BH4)2 crystallizes in the tetragonal I-4m2 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to eight H+0.50+ atoms to form distorted MgH8 hexagonal bipyramids that share edges with four equivalent BH4 tetrahedra. There are four shorter (2.03 Å) and four longer (2.08 Å) Mg–H bond lengths. In the second Mg2+ site, Mg2+ is bonded in a body-centered cubic geometry to eight equivalent H+0.50+ atoms. All Mg–H bond lengths are 2.08 Å. B3- is bonded to four H+0.50+ atoms to form BH4 tetrahedra that share an edgeedge with one MgH8 hexagonal bipyramid. There is three shorter (1.22 Å) and one longer (1.23 Å) B–H bond length. There are three inequivalent H+0.50+ sites. In the first H+0.50+ site, H+0.50+ is bonded in an L-shaped geometry to one Mg2+ and one B3- atom. In the second H+0.50+ site, H+0.50+ is bonded in an L-shaped geometry to one Mg2+ and 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.