When I apply a considerable amount of force on a carbon structure (say CNT), the bonds break.
How this bond breaking is made possible with AIREBO potential?
I want to know the mechanism that goes behind bond breaking.
Also which part of ‘LAMMPS source files’ contains the logic (code) for bond breaking?
In AIREBO, like all bond-order potentials, bonds form and break,
depending on the local geometry of clusters of atoms. What is
a “bond” changes over time naturally in such a potential.
In AIREBO potential, the C-C interactions are not defined by bond_style. So essentially there is no bond information associated with neighboring carbon atoms. They are defined by pair_style (like Vdwl interactions) in lammps, which does not require bond information to be incorporated in data file. The potential form of AIREBO itself is written in such a way that is minimum of C-C neighboring interactions occurs around its bond-length and orientation of the other carbon atoms.
Hope this helps.