Coarse–grained model based on rigid grains interaction for single layer molybdenum disulfide

Single–layer molybdenum disulfide (SLMoS₂) is a promising two–dimensional material with a wide range of possible applications in NEMS. Traditional molecular dynamics (MD) simulations of SLMoS₂ are very time–consuming and cannot be applied to the real microscopic–level systems. We develop a coarse–grained model combining the atoms of crystal lattice into rigid ‘grains’. The interaction between the grains is based on Stillinger–Weber potential with parameters recalculated to fulfill the elastic properties of the original lattice. The model is applied to calculate the phonon spectrum and for the nanoindentation problem. It is shown that in the case of small strains the model is as accurate as regular MD simulations, but uses much less interatomic interactions; hence, it is much more time–efficient.