Density-functional quantum analysis of optoelectronic, elastic, thermodynamic and hydrogen storage properties of AMgH3 (A= be, ca) perovskite-type hydrides: Prospects for clean energy hydrogen-storage fuel and optoelectronic applications

Hydrogen is a promising clean energy source to address the energy issue as well as the environmental and health risks of current energy sources. Metal hydrides have demonstrated significant potential for storing hydrogen. The perovskite hydrides AMgH3 (A = Be, Ca) have demonstrated potential for hydrogen storage applications due to their impressive gravimetric hydrogen density of 8.32 and 4.49 wt% for BeMgH3 and CaMgH3, respectively. The calculated results indicate that AMgH3 (A = Be, Ca) perovskite hydrides exhibit metallic character. The AMgH3 (A = Be, Ca) compounds mostly absorb quanta of energy in the IR range, but they also exhibit high absorption in the UV region. The formation enthalpies of these hydrides have been found to be negative, indicating that they are thermodynamically stable. Furthermore, it has been established that these perovskite hydrides are mechanically stable as they fulfil Born stability criteria.