Calculation of the relaxation properties of a dilute gas consisting of Lennard–Jones chains

The relaxation properties in the dilute-gas limit have been calculated by the classical trajectory (CT) method for a gas consisting of chain-like molecules that are rigid and interact through site–site Lennard–Jones 12–6 potentials. Results are reported for volume viscosity η V , rotational collision number ζ rot and the ratio of the rotational to self-diffusion coefficient D rot / D . The results indicate that the volume viscosity increases with temperature and decreases with chain length. The rotational relaxation of chains is efficient, as it takes of the order of 1.75–2.7 collisions to attain equilibrium. The rotational collision number is only weakly temperature dependent.