Graphene and Carbon Nanotubes are self-stressed

In the attached paper we have shown that graphene and carbon nanotubes are in a self-stress state in their natural equilibrium state, that is, the state prior to the application of external loads. We have identified different sources of self-stresses and accurately evaluated them; we have shown that they are by no means negligible with respect to load-related nanostresses.
On the one hand, our qualification of the nature of nanostresses may turn out to be a convenient starting point for future homogenization studies on carbon allotropes. On the other hand, accounting for self-stress is crucial to produce reliable predictions whenever a harmonic approximation of the interatomic potential is accepted.