DFT calculations of structural, elastic, electronic and optical properties of CaXH۳ (X= Co, Rh)

Structural, elastic, electronic and optical properties of the perovskite-type hydrides CaXH۳ (X = Co, Rh) were investigated using the first-principles full-potential linearized augmented plane wave method based on density functional theory calculations. We have investigated formation energies, lattice parameters, bulk moduli, elastic constants, electronic structures, and optical properties. Calculated negative formation energies point to their stability, and indicate that the most stable compound is CaRhH۳. In addition, elastic properties and mechanical coefficients confirm that these compounds are stable.The densities of states (DOS) in the compounds are not zero at the Fermi level reflecting their metallic behavior and the largest contributions to the partial DOS’es were observed to stem from the presence of the transition metal element. The hybridization reaction between X-d states and H-۱s states is stronger than that between Ca-d states and H-۱s states, which is an important feature for these hydrogen storage compounds.

کلیدواژه ها:

Density functional theory ، WIEN۲K code ، CaXH۳ hydrides ، Electronic ، Elastic