Relaxation in a glassy binary mixture: Comparison of the mode-coupling theory to a Brownian dynamics simulation Export

@article{citeulike:5029882, abstract = {We solved the mode-coupling equations for the Kob-Andersen binary mixture using structure factors calculated from Brownian dynamics simulations of the same system. We found; as was previously observed; that the mode-coupling temperature T c inferred from simulations is about two times greater than that predicted by the theory. However; we find that many time-dependent quantities agree reasonably well with the predictions of the mode-coupling theory if they are compared at the same reduced temperature ϵ=( T − T c )∕ T c ; and if ϵ is not too small. Specifically; the simulation results for the incoherent intermediate scattering function; the mean square displacement; the relaxation time; and the self-diffusion coefficient agree reasonably well with the predictions of the mode-coupling theory. We find that there are substantial differences for the non-Gaussian parameter. At small reduced temperatures the probabilities of the logarithm of single particle displacements demonstrate that there is hopping-like motion present in the simulations; and this motion is not predicted by the mode-coupling theory. The wave-vector-dependent relaxation time is shown to be qualitatively different from the predictions of the mode-coupling theory for temperatures where hopping-like motion is present.}, author = {Flenner, Elijah and Szamel, Grzegorz}, citeulike-article-id = {5029882}, citeulike-linkout-0 = {http://dx.doi.org/10.1103/PhysRevE.72.031508}, citeulike-linkout-1 = {http://link.aps.org/abstract/PRE/v72/i3/e031508}, citeulike-linkout-2 = {http://link.aps.org/pdf/PRE/v72/i3/e031508}, doi = {10.1103/PhysRevE.72.031508}, journal = {Physical Review E}, keywords = {diffusion, dynahetero, glass, mct, simulation}, month = {Sep}, number = {3}, pages = {031508+}, posted-at = {2009-07-01 06:15:01}, priority = {0}, publisher = {American Physical Society}, title = {Relaxation in a glassy binary mixture: Comparison of the mode-coupling theory to a Brownian dynamics simulation}, url = {http://dx.doi.org/10.1103/PhysRevE.72.031508}, volume = {72}, year = {2005} }

TY - JOUR ID - citeulike:5029882 L3 - citeulike-article-id:5029882 N2 - We solved the mode-coupling equations for the Kob-Andersen binary mixture using structure factors calculated from Brownian dynamics simulations of the same system. We found; as was previously observed; that the mode-coupling temperature T c inferred from simulations is about two times greater than that predicted by the theory. However; we find that many time-dependent quantities agree reasonably well with the predictions of the mode-coupling theory if they are compared at the same reduced temperature ϵ=( T − T c )∕ T c ; and if ϵ is not too small. Specifically; the simulation results for the incoherent intermediate scattering function; the mean square displacement; the relaxation time; and the self-diffusion coefficient agree reasonably well with the predictions of the mode-coupling theory. We find that there are substantial differences for the non-Gaussian parameter. At small reduced temperatures the probabilities of the logarithm of single particle displacements demonstrate that there is hopping-like motion present in the simulations; and this motion is not predicted by the mode-coupling theory. The wave-vector-dependent relaxation time is shown to be qualitatively different from the predictions of the mode-coupling theory for temperatures where hopping-like motion is present. IS - 3 JF - Physical Review E TI - Relaxation in a glassy binary mixture: Comparison of the mode-coupling theory to a Brownian dynamics simulation PB - American Physical Society VL - 72 SP - 031508 KW - diffusion KW - dynahetero KW - glass KW - mct KW - simulation AU - Flenner, Elijah AU - Szamel, Grzegorz PY - 2005/Sep// UR - http://dx.doi.org/10.1103/PhysRevE.72.031508 ER -