0000000000026160

AUTHOR

Markus Nauroth

Quantitative tests of mode-coupling theory for fragile and strong glass-formers

We calculate for a binary mixture of Lennard-Jones particles the time dependence of the solution of the mode-coupling equations in which the full wave vector dependence is taken into account. In addition we also take into account the short time dynamics, which we model with a simple memory kernel. We find that the so obtained solution agrees very well with the time and wave vector dependence of the coherent and incoherent intermediate scattering functions as determined from molecular dynamics computer simulations. Furthermore we calculate the wave vector dependence of the Debye-Waller factor for a realistic model of silica and compare these results with the ones obtained from a simulation o…

research product

Dynamics of a Supercooled Lennard-Jones System: Qualitative and Quantitative Tests of Mode-Coupling Theory

We present the results of a molecular dynamics computer simulation of a supercooled binary Lennard-Jones mixture. By investigating the temperature dependence of the diffusion constant and of the intermediate scattering function, we show that the ideal version of the mode-coupling theory of the glass transition is able to give a good qualitative description of the dynamics of this system. Using the partial structure factors, as determined from the simulation, as input, we solve the mode-coupling equations in the long time limit. From the comparison of the prediction of the theory for the critical temperature, the exponent parameter, the wave-vector dependence of the nonergodicity parameters …

research product

A quantitative test of the mode-coupling theory of the ideal glass transition for a binary Lennard-Jones system

Using a molecular dynamics computer simulation we determine the temperature dependence of the partial structure factors for a binary Lennard-Jones system. These structure factors are used as input data to solve numerically the wave-vector dependent mode-coupling equations in the long time limit. Using the so determined solutions, we compare the predictions of mode-coupling theory (MCT) with the results of a previously done molecular dynamics computer simulation [Phys. Rev. E 51, 4626 (1995), ibid. 52, 4134 (1995)]. From this comparison we conclude that MCT gives a fair estimate of the critical coupling constant, a good estimate of the exponent parameter, predicts the wave-vector dependence …

research product

Dynamics of a Supercooled Lennard-Jones System: Qualitative and Quantitative Tests of Mode-Coupling Theory

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 amp…

research product