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.