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

Quantum chemical calculations have been carried out to investigate the hydrogen storage capacity of Be 2 (NLi) 2 cluster. Calculations reveal that the cluster can take up to eight H 2 molecules reaching a maximum gravimetric density of 21.04 wt%. Six H 2 molecules bind at the Li atoms and two H 2 bind at the Be atoms with moderate binding energy which is required for reversible storage of H 2 . 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 H 2 molecules are strongly bound at 77 K and get slowly released at elevated temperatures.