Energetics and electronic properties of Mg7TMH16 (TM = Sc, Ti, V, Y, Zr, Nb): An ab initio study

Abstract First-principles calculations have been performed on the face-centered cubic (FCC) magnesium–transition metal (TM) hydrides Mg 7 TMH 16 (TM=Sc, Ti, V, Y, Zr, Nb). The cohesive energies are calculated to analyze the stability, and the obtained enthalpies of formation for hydrides Mg 7 TMH 16 have been used to investigate the possible pathways of formation reaction. The calculated enthalpy changes show that the decomposition temperatures of Mg 7 TMH 16 are lower than that of MgH 2 . The electronic densities of states reveal that all the hydrides studied here exhibit metallic characteristics. The bonding nature of Mg 7 TMH 16 is investigated, showing stronger covalent bonding between TM and H than between Mg and H.