Dynamics of a supercooled Lennard-Jones system: Qualitative and quantitative tests of mode-coupling theory

Abstract

Using a molecular dynamics computer simulation we investigate the dynamics of a supercooled binary Lennard-Jones mixture. At low temperatures this dynamics can be described very well by the ideal version of mode-coupling theory. In particular we find that at low temperatures the diffusion constants show a power-law behavior, that the intermediate scattering functions obey the time temperature superposition principle, and that the various relaxation times show a power-law behavior. By solving the wave-vector dependent mode-coupling equations we demonstrate that the prediction of the theory for the wave-vector dependence of the nonergodicity parameters and the r-dependence of the critical amplitudes are in good agreement with the one determined from the computer simulation, which shows that the theory is also able to make quantitative correct predictions.