The effect of hydrojen on the mechanical and vibrational properties of LaMgNi4Hx (x=1, 4, 7)

In this work, the first principles calculations have been performed in order to predict the mechanical, lattice dynamical and thermodynamical properties of the LaMgNi4 compounds as well as its hydrides LaMgNi4H, LaMgNi4H4, and LaMgNi4H7. These properties of the compounds are investigated by using the generalized gradient approximation (GGA) based on density functional theory. The calculated lattice parameters are in excellent agreement with the experimental and theoretical data. It is shown that all compounds are exhibit both mechanical and dynamical stability. The effect of hydrogen concentration on the mechanical and vibrational properties are also discussed.