A generalised FK model for the 558 line defect in graphene

Defects in two-dimensional nanomaterials do not always affect their properties negatively, but often have useful functionality. The 558 line defect in graphene distinctively acts as a quasi-one-dimensional metallic wire and a valley filter, which is already experimentally realised. To have a thorough understanding of the 558 line defect in graphene, we have extended the conventional FK model and have applied the model to theoretically investigate the structure of the 558 line defect, which agrees well with the first-principle simulation result. In the generalised FK model, it is vital to take into account bond energy correction to the interatomic force of atoms on the defect line. The generalised FK model can be used to predict structures of one-dimensional topological defects in other two-dimensional materials.