Theory of carbon nanocones: Mechanical chiral inversion of a micron-scale three-dimensional object

The high symmetry of the conical structure and the local reflection symmetry of a graphene sheet were investigated. Cones with from one to three pentagonal defects at the apex were analyzed. The final state was an atomically exact chiral invert of the original system for chiral cones. The maximal yield strength of the cone was found to increase by ∼40% when the local reflection symmetry of the graphene sheet was broken by the chemisorption of just five hydrogen atoms to the apex. The results show that the presence of a substrate and indenter prevent the nanocones from finding the metastable configurations.