Cell Multipole Method for Molecular Simulations in Bulk and Confined Systems
CALIFORNIA INST OF TECH PASADENA MATERIALS AND PROCESSES SIMULATION CENTER
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One of the bottlenecks in molecular simulations is to treat large systems involving electrostatic interactions. Computational time in conventional molecular simulation methods scales with ON2, where N is the number of atoms.With the emergence of new simulations methodologies, such as the cell multipole method CMM, and massively parallel supercomputers, simulations of 10-million atoms or more have been performed. In this work, the optimal hierarchical cell level and the algorithm for Taylor expansion were recommended for fast and efficient molecular dynamics simulations of three-dimensional 3D systems. CMM was then extended to treat quasi-two-dimensional 2D systems, which is very important for condensed matter physics problems. In addition, CMM was applied to grand canonical ensemble Monte Carlo simulations for both 3D and 2D systems. Under the optimal conditions, our results show that computational time is approximately linear with N for large systems, average error in total potential energy is about 0.05 for 3D and 0.32 for 2D systems, and the RMS force error is 0.27 for 3D and 0.43 for 2D systems when compared with the Ewald summation.
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