Simulation of polymer melts: From spherical to ellipsoidal beads

In a previous work([1]) we presented a coarse-graining procedure for bonded interactions, while spherical, purely repulsive 6-12 interactions were use d to account for the excluded-volume of the beads of the phantom chains. He re we extend this approach towards ellipsoidal beads whose shapes are extra cted from the geometry of the underlying atomistic chains. The influence of the bead shapes on the static and dynamical properties of melts are studie d in detail for two modifications of polycarbonates, from 2mers up to 20mer s. The results obtained in both cases are discussed in the context of corre sponding experiments and atomistic simulations.