Structure and Stability of Tube and Cage Ge60H60

A tube Ge60H60 isomer in D5d symmetry with fused five-membered rings located at the ends of the tube is more stable than the fullerene-like Ih cage isomer at the B3LYP/cc-pVDZ level of theory. Introducing endo Ge−H bonds increases the stability of both cage and tube isomers. The most stable tube isomer can admit six endo Ge−H bonds. The cage isomer can admit 10−12 endo Ge−H bonds (H10@Ge60H50 and H12@Ge60H48), and they also represent the most stable Ge60H60 isomers. The stability order and structural patterns of Ge60H60 are the same as those found for the corresponding Si60H60 isomers. Moreover, it is found that the 6-31G(d,p) basis set fails to predict the relative energies of the Ge60H60 isomers and the Ge6H6 isomers.