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

A molecular dynamics (MD) simulation, which includes all degrees of freedom of atomic motion, has been carried out in order to investigate the tempera ture dependence of single particle dynamics such as translational and reori entational motions of liquid benzene (C6H6). The translational diffusion co efficients D and first and second rank reorientational correlation limes ta u(lR) (l = 1, 2) of liquid C6H6 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 cha racteristic of typical molecular liquids. Although these simulated D and ta u(lR) values slightly deviate from experimental ones, both activation energ ies E-a of simulated and experimental ones are in agreement with each other . The Stokes-Einstein-Debye (SED) equations, which are based on a hydrodyna mics model, have also been checked for the D and tau(lR) values with changi ng temperature. It has been found that the SED equations hold for both valu es, and the hydrodynamical model is effective for the simulated liquid C6H6 . (C) 1999 Elsevier Science B.V. All rights reserved.