failure criterion of the cutoff for the bonds of bond_style harmonic or morse

Hi all,
I went over the work of coarse grained model of multi-layer graphene,C A R B O N 8 2 ( 2 0 1 5 ) 1 0 3 –1 1 5,but when I went to extend the model to larger system,I have met the obstacle of failure criterion of the cutoff for the bonds, which I think is important for failure strain of materials.so I want to ask some information of the bond cut off for harmonic or morse bond style.

Dose bond cut off related to the bond length?and how?
Dose bond cut off related to the energy?and how?

Bonds do not normally have a cutoff. E.g. a harmonic

or Morse bond will act on the two atoms no matter

how far apart they get. In the case of harmonic that

will lead to a huge attractive force.

It sounds like you want a bond potential that allows

for a bond to break. See bond style quartic for an example.

If you use a bond-order potential like (AI)REBO for graphene

then there are no fixed bonds. Bonds form and break

freely due to the pair style itself and the geometry

of the atoms.

Steve