Crystal structure and stability of magnesium borohydride from first principles

We present a structure model for constructing Mg(BH(4))(2). The first-principles calculations reveal that some stable ground-state crystal structures of Mg(BH(4))(2) have the same or slightly lower energy than the I-4m2 structure predicted in a paper by Ozolins [Phys. Rev. Lett. 100, 135501 (2008)]. The possible mechanism for the anomalous stability originates from the fact that the charge transfer between different atoms is more homogeneous. The structure model can be anticipated to have potential application for predicting new stable structures of this group of homologous materials.