Temperature dependence of single particle dynamics of flexible liquid benzene using molecular dynamics simulation

Abstract

A molecular dynamics (MD) simulation, which includes all degrees of freedom of atomic motion, has been carried out in order to investigate the temperature dependence of single particle dynamics such as translational and reorientational motions of liquid benzene (C 6H 6). The translational diffusion coefficients D and first and second rank reorientational correlation times τ lR ( l=1, 2) of liquid C 6H 6 are simulated at 366.12, 322.69, 295.00 and 198.54 K. Except for the simulation at 198.54 K, all three motions are characteristic of typical molecular liquids. Although these simulated D and τ lR values slightly deviate from experimental ones, both activation energies E a of simulated and experimental ones are in agreement with each other. The Stokes–Einstein–Debye (SED) equations, which are based on a hydrodynamics model, have also been checked for the D and τ lR values with changing temperature. It has been found that the SED equations hold for both values, and the hydrodynamical model is effective for the simulated liquid C 6H 6.