Molecular Dynamics simulations of rod-like polyelectrolytes

We present theoretical and numerical results on stii, linear polyelec-trolytes within the framework of the cell model. With the help of an innec-tion point criterium we discuss counterion condensation for systems with added salt. Molecular dynamics simulations of the cell model are used to show, under which circumstances the mean-eld Poisson-Boltzmann theory fails qualitatively. We present measurements of the osmotic co-eecient, which can become negative when multivalent counterions are present, leading to eeective attractions. To facilitate the comparison to experiments , we compute the osmotic coeecient for poly(para-phenylenes). We also present rst investigations of ion-ion correlations and compare them to predictions of the recently advocated Wigner crystal theories.