Computational quantum hydrogen storage properties of novel double perovskite Na2BeCdH6 hydrides: Structural, elastic, electronics, mechanical, and thermodynamics frontiers of comprehensive DFT study

The scarcity of fuel in the modern era has drawn the most attention to hydrogen storage (H 2 ) gases. Applications involving the synthesis and hydrogen storage depend heavily on perovskite materials. As a result, research on hydrogen storage applications mostly focuses on analyzing the hydrogen capacities of recently released substances. This work uses the Na 2 BeCdH 6 compounds to study various physical and H 2 capacity features by using density functional theory (DFT) with the CASTEP algorithm. The compounds being studied have been optimized inside the cubic structure of Na 2 BeCdH 6 , with optimized volumes and lattice constants of 400.44 Å 3 and 7.37 Å, respectively. Moreover, band structure calculation indicates that Na 2 BeCdH 6 compound possesses a bandgap of 0.0 eV, confirming the compound’s conductor properties. In addition, these materials meet inherent stability requirements for mechanical characteristics that are based on elastic constant (C ij ) values. In addition, Pugh's ratio (0.24) and Cauchy pressure (1.63) show that Na 2 BeCdH 6 has a brittle nature. These hydrides have negative values for their formation energy (-113.305) and tolerance factor (0.92), indicating that they are structurally and thermally stable compounds. The gravimetric ratio of H 2 storage density was observed to be 3.369 wt%, which makes it potentially useful for hydrogen storage applications. It is noted that these compounds are easily synthesized for practical commercial applications. Our finding predicts that the said compounds are superior for hydrogen storage capacities.