A parallel algorithm for the concurrent atomistic-continuum methodology

Abstract

In this work we present a parallel algorithm for the Concurrent Atomistic Continuum (CAC) formulation that can be integrated into existing molecular dynamics codes. The CAC methodology is briefly introduced and its parallel implementation in LAMMPS is detailed and then demonstrated through benchmarks that compare CAC simulation results with corresponding all-MD (molecular dynamics) results. The parallel efficiency of the algorithm is demonstrated when simulating systems represented by both atoms and finite elements. The verification benchmarks include dynamic crack propagation and branching in a Si single crystal, wave propagation and scattering in a Si phononic crystal, and phonon transport through the phase interface in a PbTe/PbSe heteroepitaxial system. In each of these benchmarks the CAC algorithm is shown to be in good agreement with MD-only models. This parallel CAC algorithm thus offers one of the first scalable multiscale material simulation methodologies that relies solely on atomic-interaction models.