An improved smoothed molecular dynamics method with high‐order shape function

Abstract

As an efficient molecular simulation method, the smoothed molecular dynamics (SMD) method introduces background mesh and mapping process into molecular dynamics (MD) procedure to suppress high‐frequency modes, so that a much larger time step than that of MD can be adopted. SMD method can achieve a nice overall accuracy, but local atomic disorders cannot be described very well with original SMD method for smoothing out high‐frequency motions. An improved SMD method with two kinds of high‐order shape functions is proposed. A parameter indicating the smoothing degree in SMD method is also presented to assess the mapping process. The efficiency and the accuracy of the improved method are discussed in detail, and the proposed method is validated with several examples. The results demonstrate obvious improvement in accuracy, and more high‐frequency atomic motions can be captured. When the high‐order SMD method is coupled with the MD method, the non‐physical phonon reflection, which may occur at the interface in the coupling of MD and original SMD method, will decrease remarkably even if no transition scheme is employed.