A topology preserving method for generating equilibrated polymer melts in computer simulations

A new method for generating equilibrated configurations of polymer melts is presented. In this method, the molecular weight of an equilibrated melt of polymers is successively doubled by affinely scaling the simulation box and adding beads along the contour of the chains. At each stage of molecular weight doubling, compressive deformations are produced on all length scales, while the random walk nature of the polymers is preserved, thereby requiring relaxation times significantly smaller than the reptation time to fully equilibrate the melt. This method preserves the topological state of individual polymers in the melt and its effectiveness is demonstrated for linear polymers with molecular weight N up to 1024, and cyclic polymers with N up to 8192. For the range of N studied, the method requires simulation time that scales as N(2) and is thought to be applicable to a variety of polymer architectures.