  The newly developed compound ExBox4+ is explored to check whether it is a
proficient hydrogen storage material. Both exoherdal and endohedral hydrogen
adsorption on ExBox4+ are studied. Endohedral hydrogen molecules interact
strongly than exohedral ones. The hydrogen adsorption energy is as good as the
recently studied charged fullerenes. The hydrogen storage capacity appears to
be ~4.3 wt%. The endohedral CO sorption is also analysed with the help of DFT.
The first principle DFT calculation and MD simulation are performed to
investigate the effect of lithium doping on the gas adsorbing capacity and
adsorption enthalpy as well as adsorption energy of ExBox4+.The metal atom
interaction with ExBox4+is found to be pretty strong, and the interaction
energy appears to be higher than the metal cohesive energy.The thermodynamic
parameters suggest that metal doping method is spontaneous in nature. The
analysis of adsorption energy, thermodynamic properties and MD simulation
results suggest that Li doped ExBox4+ can be a promising gas adsorbing
material. Lithium doping increases the gas adsorption capacity of ExBox4+. The
Li decorated ExBox4+ is found to adsorb twenty four hydrogen molecules with a
gravimetric wt% of 6.23. Adsorption of CO on the metal decorated ExBox4+ is
also studied. AIM analysis is performed to obtain a general idea of the bonding
interaction between Li-H and Li-C.
