First-principles computation of hydrides-perovskites XZrH3 (X = Ba, Ca, and Sr): evaluation of structural, electronic, optical and mechanical properties for hydrogen storage

In the current study, the physicochemical properties of the hydride perovskite XZrH3 (X = Ba, Ca, and Sr) are thoroughly investigated using first-principles calculations. Structural calculations indicate that the BaZrH3, CaZrH3, and SrCuH3, with lattice values of 4.27, 4.01, and 4.12, are synthesizable and thermodynamically stable. The density of states (DOS) and electronic band structure analysis of XZrH3 (X = Ba, Ca, and Sr) perovskites reveal metallic behavior. Apart from that, simulations were performed for the refractive index, reflectivity, dielectric function, and energy-loss functions. The shear and Young's moduli, as well as the Poisson's ratio, are calculated for novel polycrystalline materials, and the results proved that compounds with the formula XZrH3 (X = Ba, Ca, and Sr) are ductile. The analysis of the hydrogen storage features of the BaZrH3, CaZrH3, and SrZrH3 has revealed that they have gravimetric hydrogen storage capacities of 1.307 wt%, 2.251 wt%, and 1.662 wt%, respectively. Overall, the results offer a feasible strategy for creating novel, potentially beneficial perovskite-type hydrides for hydrogen storage.