A spatial upscaling method for describing the three-body potential of a diamond lattice structure

A spatial upscaling method that efficiently describes the three-body potential of diamond lattice structures is proposed in this paper. The spatial scale of the bulk single-crystal diamond can be increased without increasing the computational complexity by balancing the weighting factor with the atomic-scale Tersoff potential and the mass of its constituents. The statistical averages and fluctuations in the thermodynamic equilibrium were reproduced within acceptable error limits. The model used to represent the mechanical behavior of diamond-structured materials was further expanded to simulate polycrystalline diamond structures under mechanical deformation. An empirical scaling formula was applied to attenuate localized stresses generated at the surfaces and grain boundaries. The upscaled model successfully reproduced the deformation energy distribution under spherical indentation observed from the all-atom-based simulation model.