First Principles Study of Electronic Structure, Structural Properties and Superconductivity of Nickel Hydride

Abstract

First principles calculation were performed using Tight-binding LMTO method with Local density approximation (LDA) and Atomic sphere approximation (ASA) to understand the electronic properties of  Nickel Hydride. The equilibrium geometries, the electronic band structure, the total and partial DOS are obtained under various pressures and are analyzed in comparison with the available experimental and theoretical data. The most stable structure of NiH is NaCl structure, NiH 2 is CaF 2 structure and NiH 3 is AlH 3 structure at normal pressure. Our result indicates that the maximum storage capacity achieved was 4.9% for NiH 3 . In particular there is a non occurrence of superconductivity in NiH. But an increase in Tc is predicted due to the addition of H atoms. The obtained Tc values for NiH 2 and NiH 3 are 5K and 10K respectively at normal pressure. Also, it is found that the Tc value increases as the pressure increases.