Structural, electronic, elastic, vibrational and thermodynamic properties of ZrNi and ZrNiH3: A comprehensive study through first principles approach.

Zirconium based alloys have potential applications in automobile, energy and spacecraft industries. The structural, electronic, elastic, vibrational and thermodynamic properties of orthorhombic ZrNi and ZrNiH 3 are studied in detail using the projector augmented wave method and the generalized gradient approximation based on density functional theory. The optimized lattice parameters of both ZrNi and ZrNiH 3 agree well within ±1% from the experimental values. The electronic structure analysis shows significant contribution of 4 d and 3 d orbitals of Zr and Ni to the fermi energy level, respectively and along with signatures of two types of hydrogen atoms occupying the lattice of ZrNiH 3 . Elastic property calculation of these two compounds showed mechanical stability and anisotropy at ambient pressure. In addition, the phonon calculation of both the compounds showed that ZrNi is dynamically stable but ZrNiH 3 is dynamically unstable. The formation energies (Δ f H ) of ZrNi and ZrNiH 3 at 0 K, after zero point energy correction, have been estimated to be −41.87 kJ/mol and −78.25 kJ/mol H 2 , respectively. The temperature dependent thermodynamic functions of ZrNi and ZrNiH 3 have also been calculated from the Debye-Grüneisen quasi-harmonic approximation. [ABSTRACT FROM AUTHOR]