A DFT investigation on structural, electronic, magnetic, optical, elastic and hydrogen storage properties of Ru-based hydride-perovskites XRuH (X = Cr, V, Ni).

The present investigation delves into various physical properties exhibited by CrRuH, VRuH and NiRuH. Notably adopting a stable cubic configuration, both compounds manifest a distinct metallic demeanor characterized by an absolute absence of band gap. In-depth analysis through Total Density of States (TDOS) and Partial Density of States (PDOS) justify this metallic conduct by distinctly showcasing peak conductivity at the Fermi level. The materials' magnetic behavior reveals an antiferromagnetic disposition for CrRuH and NiRuH, while their intrinsic attributes emerge as anisotropic and rigid. Applying Poisson's ratio () and the / ratio, all investigated compounds show ductility, but the CrRuH is superior among them. The heightened values of Young's modulus, Bulk modulus, and mean shear modulus observed in CrRuH underscore its enhanced rigidity as compared to VRuH and NiRuH. Within the optical realm, CrRuH displays notable optical conductivity and absorption, particularly within the lower energy spectrum. Remarkably, at 0 eV, CrRuH showcases elevated reflectivity and refractive index as compared to the other investigated materials. On the hydrogen storage front, XRuH (X = Cr, V, Ni) exhibit promising potential, yet CrRuH emerges as the more favorable candidate for hydrogen storage applications.