Rattling of carbon disulphide molecules in liquids Original Research Article

Molecular dynamics simulations of 256 carbon disulphide molecules are carried out for temperatures and densities along the saturated vapour curve. We consider correlation functions and sign correlation functions for the angular velocity and components of the translational velocity parallel and perpendicular to the molecular axis. The correlation functions are analyzed using a model based on uncorrelated successive velocity reversals. In calculations of the time intervals between successive velocity reversals we use the “Cartesian coordinate oscillation” criterion as well as the “right-angle turn” one. The obtained results show that the model with the Cartesian coordinate oscillation criterion describes the main features of the velocity sign correlation functions and it can be used to study not only translational but also reorientational motion of molecules in real liquids.