MOLECULAR-DYNAMICS FOR POLYMERIC FLUIDS USING DISCONTINUOUS POTENTIALS

Molecular dynamics simulation techniques for systems interacting with discontinuous potentials are discussed. Optimization and efficiency te chniques are summarized for performing discontinuous molecular dynamic s on serial computers with direct application to polymer-like fluids. Comparisons are presented for two algorithms: (1) single-event schedul ing, and (2) multiple-event scheduling. The single-event scheduling al gorithm is approximately 75% faster than the multiple-event scheduling algorithm for molecular fluids but yields equivalent performance for atomic fluids. For the single-event scheduling method, a combination o f link lists and neighbor lists are used when searching for possible p article interactions. The combination of efficiency techniques permits multibillion time step simulations for relatively large systems on de sktop workstations. Both discontinuous molecular dynamics codes for si ngle and multiple-event scheduling algorithms are available on the int ernet. The utility of the method is demonstrated for entangled chains, tethered chains, and heteronuclear chain mixtures. (C) 1997 Academic Press.