Hydrogen storage capacity of C(60)(OM)(12) (M=Li and Na) clusters.

By using density functional theory, the hydrogen storage capacity of C(60)(OM)(12) (M=Li and Na) clusters has been studied. The atomic charge transfer process has been analyzed to explain the reason why H(2) molecules can be attracted. Through our calculation, we found that C(60)(OM)(12) (M=Li and Na) possesses an adequate hydrogen binding energy which is suitable for practical storage usage at ambient temperature. When these clusters reach their maximum H(2) uptake capacity, the mean hydrogen binding energy is 0.115 eV/H(2) for C(60)(OLi)(12)54H(2) and 0.122 eV/H(2) for C(60)(ONa)(12)54H(2) with the gravimetric hydrogen percentage of 9.78 and 8.33 wt %, respectively.