▎ 摘　　要

There is a growing need to understand the stability of quasi-one-dimensional one-layer-thick graphene nanoribbons. Objective molecular dynamics based on density-functional tight-binding models are used to investigate the stability against torsional deformations of nanoribbons with bare, F-, and OH-decorated armchair edges. The prevalence of chiral nanoribbons, including homochiral ones, prompted the construction of a simple phenomenological model inspired from the Landau phase transition theory. Our model is based on atomistic data and gives the structural parameters of the nanoribbon as a function of its edge chemistry and axial strain. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4770002]