Fuzzy clustering approach to hierarchical molecular dynamics simulation of multiscale materials phenomena

A new algorithm is developed for large-scale, long-time molecular dynamics simulations of multiscale materials phenomena by combining a hierarchy of subdynamics: (i) rigid-body cluster dynamics for global conformational changes; (ii) implicit integration of Newton's equations for the coalescence of the clusters; and (iii) normal-mode analysis of fast atomic oscillations, Fuzzy clustering is used to facilitate the seamless integration of the multiple levels of abstraction, The fuzzy-body/implicit-integration/normal-mode (FIN) scheme speeds up a simulation of nanocluster sintering by a factor of 28 over a conventional explicit integration scheme. A parallel implementation of the scheme achieves an efficiency of 0.94 for a 12.7 million-atom nanocrystalline solid on 64 nodes of an IBM SP2 computer. (C) 1997 Elsevier Science B.V.