Hybrid method combining atomic model and continuum

Kim, G.; Senda, Yasuhiro*

We have proposed a new hybrid method coupling an atomic model and a continuum model by extending Andersen's constant-pressure molecular dynamics method. In Lagrange function of the hybrid model, we introduce displacements field of the continuum as a new degree of freedom. We applied our method to a one-dimensional hybrid model which was composed of an atomic chain of argon atoms and springs and calculated the density of states of phonons in the atomic chain. As a result, we reveal that the large-scale fluctuation in the atomic chain generates a variety of states of phonons. The result from our hybrid method is consistent with that obtained by the conventional MD method. We also applied our method to an atomic defect model and investigated effect of atomic defects on the macroscopic continuum.