Pair and singlet diffusion in a Lennard-Jones liquid

Abstract
Inspired by the experimental work of Richter et al. [1], we have investigated the dynamic behaviour of pairs of particles of a Lennard-Jones liquid for four different thermodynamic states. The short and long time behaviour of dynamic correlation functions of pairs are studied and directly compared with that of single particle correlation functions. Only those relating to singlet and pair diffusion are treated. A list of the correlation functions considered in this work is presented in the table of the Appendix. The main results are the following: Our results, obtained by extensive molecular dynamics (MD) calculations, are in quantitative disagreement with results generated by other authors [3, 4], and the findings of Posch et al. [6] could not be confirmed in detail by our work.