Ultra-high reversible hydrogen storage capacity of the Li 4 B 2 cluster: a quantum chemical study.

Quantum chemical calculations have been carried out to investigate the hydrogen adsorption characteristics of the Li 4 B 2 cluster. Calculations reveal that the cluster can adsorb a maximum of thirteen H 2 molecules reaching a considerably high gravimetric density of 34.66 wt%. The nature of the interaction between the H 2 molecule and Li center has been investigated within the realm of quantum theory of atoms in molecules which revealed the non-covalent character. The fate of H 2 absorption by the cluster has been studied in the course of a 2000 fs time evolution through Born-Oppenheimer molecular dynamics simulations at different temperatures. The outcomes reveal that the H 2 molecules are strongly bound at 77 K and get slowly released at elevated temperatures.