Hybrid functional calculations of potential hydrogen storage material: Complex dimagnesium iron hydride

By employing the state of art first principles approaches, comprehensive investigations of a very promising hydrogen storage material, Mg₂FeH₆ hydride, is presented. To expose its hydrogen storage capabilities, detailed structural, elastic, electronic, optical and dielectric aspects have been deeply analysed. The electronic band structure calculations demonstrate that Mg₂FeH₆ is semiconducting material. The obtained results of the optical bandgap (4.19 eV) also indicate that it is a transparent material for ultraviolet light, thus demonstrating its potential for optoelectronics application. The calculated elastic properties reveal that Mg₂FeH₆ is highly stiff and stable hydride. Finally, the calculated hydrogen (H₂) storage capacity (5.47 wt.%) within a reasonable formation energy of −78 kJ mol⁻¹, at room temperature, can be easily achievable, thus making Mg₂FeH₆ as potential material for practical H₂ storage applications.