A computer simulation of the dynamical properties of diatomic fluids

✍ Scribed by Gerard H. Wegdam; Gareth J. Evans; Myron Evans

• Publisher: Elsevier Science
• Year: 1977
• Weight: 654 KB
• Volume: 11
• Category: Article
• ISSN: 0378-4487
• DOI: 10.1016/0378-4487(77)80042-3

✦ Synopsis

The recently developed Tildesley/Streett molecular dynamics algorithm [l] for the motion of 256 atom-atom Lennard-Jones potentials is used to study the behaviour of five autocorrelation functions: linear and angular velocity, orientation, torque and force under the following conditions. (i) Increasing number density (p\* ) at constant temperature (T\) and interatomic distance (d\); (ii) increasing d\* at constant T\* and p\; (iii) increasing T\ at constant p\* and d\. The following indications appear (i). The mean square torque and force can exhibit maxima or minima as a function of p\ or d\, but over a restricted range, seem linear in T\ at constant p\* and d\. (ii) Autocorrelation functions of high derivatives of the intera omit vector u or the angular velocity w decay generally on the same time scale as the vectors themselves, and become more complicated functions of time. These data do not support an early truncation of the Mori continued fraction with a simple function.
(iii) The effect of elongation at constant p\ on dynamical properties such as the above is much more pronounced than that of p\* at constant d\* indicating that hard-core anisotropy is the important factor in the determination of, for example nematic behaviour.