MOLECULAR-DYNAMICS STUDY OF BINARY ALLOYS: DYNAMICAL CORRELATIONS OF THE SUPERCOOLED LIQUIDS NEAR THE GLASS TRANSITION OF BINARY SOFT-SPHERE MIXTURES

With the aid of molecular-dynamics simulations of soft-sphere mixtures we have computed the longitudinal and transverse collective modes (sound waves). The shear stress autocorrelation function is also computed. It is shown that the stress autocorrelation function exhibits characteristic slow relaxation phenomena (long-time tails) near and beyond the glass transition, compatible with the previous result obtained from the density autocorrelation functions. However, the decaying form of both functions at long times appears to be significantly different.