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A Density Functional Study of α-Mg(BH4)2

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journal contribution
posted on 12.08.2008 by Michiel J. van Setten, Gilles A. de Wijs, Maximilian Fichtner, Geert Brocks
Boranates (tetrahydroborates) are studied intensively because of their potential use as hydrogen storage materials. In this Article, we present a first-principles study of α-Mg(BH4)2 at the level of density functional theory. We optimize the complex structure of α-Mg(BH4)2, starting from the experimental crystal structures with 30 formula units per unit cell. From total energy calculations, incorporating vibrational contributions at finite temperature, we show that the hydrogen desorption reaction α-Mg(BH4)2 → MgB2 + 4H2 has a reaction enthalpy of 38 kJ/mol H2 at room temperature. This makes Mg(BH4)2 an interesting candidate as a hydrogen storage material.