Molecular dynamics simulation of thermal ripples in graphene with bond-order-informed harmonic constraints

We describe the results of atomistic molecular dynamics simulations of thermal rippling in graphene with the use of a generic harmonic constraint model. The distance and angular constraint constants are calculated directly from the second-generation bond-order interatomic potential that describes carbon binding in graphene. We quantify the thermal rippling process in detail by calculating the overall rippling averages, the normal-normal correlation distributions and the height distributions. In addition, we consider the effect of a dihedral angular constraint, as well as the effect of sample size on the simulated rippling averages. The dynamic corrugation morphologies of simulated graphene samples obtained with the harmonic constraint model at various temperatures are, overall, consistent with those obtained with the bond-order potential and are in qualitative accord with previously reported findings. Given the wide availability of the harmonic constraint model in various molecular mechanics implementations, along with its high computational efficiency, our results indicate a possible use for the presented model in multicomponent dynamic simulations, including atomically thin layers.