摘要

We propose a class of efficient matching boundary conditions to suppress spurious reflection for multiscale computations of one dimensional diatomic chains. This provides the first local effective treatment of both acoustic and optical phonons. Adopting the extended zone scheme of the dispersion relation, we design a class of force boundary conditions by enforcing perfect absorption at certain selected wave numbers. Reflection suppression is improved by involving more neighboring atoms in the condition. The effectiveness of the proposed matching boundary conditions is demonstrated by reflection coefficient analysis, numerical tests, and comparisons with the time history treatment.