Hydrogen storage capacity of Be₂ (NLi)₂ cluster with ultra-short beryllium-beryllium distance

Quantum chemical calculations have been carried out to investigate the hydrogen storage capacity of Be₂ (NLi)₂ cluster. Calculations reveal that the cluster can take up to eight H₂ molecules reaching a maximum gravimetric density of 21.04 wt%. Six H₂ molecules bind at the Li atoms and two H₂ bind at the Be atoms with moderate binding energy which is required for reversible storage of H₂ . Symmetry-adapted perturbation analysis reveals the significant contribution of electrostatic and induction and very minor contribution of dispersion toward the total interaction energy. Molecular dynamics simulations reveal that the H₂ molecules are strongly bound at 77 K and get slowly released at elevated temperatures.