Young's moduli of carbon materials investigated by various classical molecular dynamics schemes

Highlights: • Systematic investigation of classical carbon potentials in view of their predictive power for carbon-based materials. • Evaluation of Young's moduli for three archetypical carbon materials for many popular carbon potentials implemented in LAMMPS. • Investigation provides information on which potential to choose for certain investigations especially in view of the growing importance of carbon materials. • EDIP carbon potential of Marks appears superior to all carbon potentials so far implemented in LAMMPS. For many applications classical carbon potentials together with classical molecular dynamics are employed to calculate structures and physical properties of such carbon-based materials where quantum mechanical methods fail either due to the excessive size, irregular structure or long-time dynamics. Although such potentials, as for instance implemented in LAMMPS, yield reasonably accurate bond lengths and angles for several carbon materials such as graphene, it is not clear how accurate they are in terms of mechanical properties such as for instance Young's moduli. We performed large-scale classical molecular dynamics investigations of three carbon-based materials using the various potentials implemented in LAMMPS as well as the EDIP potential of Marks. We show how the Young's moduli vary with classical potentials and compare to experimental results. Since classical descriptions of carbon are bound to be approximations it is not astonishing that different realizations yield differing results. One should therefore carefully check for which observables a certain potential is suited. Our aim is to contribute to such a clarification.