The N-body interatomic potential for carbon: Influence of the precision of three-body interactions’ contribution on the accuracy of molecular dynamics simulations

In molecular dynamics simulations, there are dozens of potentials of different type, which take into account the angular dependence of the potential energy, for describing the interactions in carbon. Each of them describes simultaneously only a part of its physical properties. Meanwhile, a recently developed N-body approach provides the ability to set the required precision of this angular dependence. In particular, in this work we will show how accuracy in describing three-body interactions influences the accuracy of reproduction of physical properties of carbon on the example of one and two basis functions for these interactions. For both potentials, the identical optimization procedure, including fitting database and weights of each target value, was performed. We found that the last one reproduces the structural, elastic and defect properties of diamond, graphite and graphene phases of carbon in better agreement with experimental and theoretical data than the potential with only one basis function. For additional benchmark of this potential we assessed the melting point of graphite, which is predicted in an acceptable agreement with the experimental value. [Display omitted] •A new interatomic potential for carbon was developed.•An increase of basis functions improves the description of carbon structures.•The potential with one functions predicts graphite structures as unstable.•The potential with two functions predicts three main carbon structures as stable.