Ab initio study of electronic and thermodynamic properties of NdNi4Mg and NdNi4MgH4

The crystal and electronic structure and the thermodynamic properties of NdNi4Mg and its hydride NdNi4MgH4 have been investigated by means of first-principles calculations. The calculated structural parameters are found to be in very good agreement with experimental data. The total electronic density of states shows that NdNi4MgH4 is still metallic. Taking into account zero-point corrections, the obtained enthalpies of formation for NdNi4Mg and NdNi4MgH4 are -224 and -290 kJ mol(-1), respectively. The reaction enthalpy for dehydrogenation of NdNi4MgH4 is only 33.0 kJ mol(-1) H-2, which proves theoretically that NdNi4MgH4 has a low dissociation temperature. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.