The Molecular Mechanics Model of Carbon Allotropes

Carbon can form numerous allotropes because of its valency. Graphene, carbon nanotubes, capped carbon nanotubes, buckyballs, and nanocones are well-known polymorphs of carbon. Remarkable mechanical properties of these carbon atoms have made them the subject of intense research. Several studies have been conducted on carbon nanotubes or graphene. In the present study, the molecular mechanics method was applied to model five polymorphs of carbon with a uniform approach and compare the allotropes of carbon in detail. Also, we obtained Young’s modulus and natural frequencies for every form of carbon, which can be useful for researchers. We found that an increase in the diameter of the carbon nanotube would accompany with a drop in its strength and Young’s modulus. Moreover, our results show that the capped carbon nanotube has a higher strength compared to that of the non-capped nanotube, which might be due to the end bonds of the carbon nanotube. Finally, we identified extraordinary properties of Buckyball including its strength, which is three times more than that of the carbon nanotube with the same diameter.