MONTE-CARLO CALCULATION OF THE OSMOTIC 2ND VIRIAL-COEFFICIENT OF OFF-LATTICE ATHERMAL POLYMERS

The osmotic second virial coefficient, B2, of off-lattice athermal polymers is calculated using a Monte Carlo procedure. Chain lengths, n, ranging from 3 to 128 are studied. We find that B2/n2 is-similar-to n-0.25+/-0.02 for n --> infinity consistent with scaling theories but different from earlier Monte Carlo estimates. The predictions of B2 from various analytical equations of state for hard chains are tested against the simulation results and found to be quite poor. The generalized Flory dimer equation is modified by forcing it to reproduce the Monte Carlo values for the second virial coefficient; this significantly improves the compressibility factor predictions of the theory at low densities.