MOLECULAR-DYNAMICS STUDY FOR THE GLASS-TRANSITION IN LII

By means of constant-pressure, constant-temperature molecular dynamics simulations, we have studied the glass transition of LiI. We have calculated both static and dynamic properties with microscopic analyses for ionic motions. The main emphasis of this work is on the dynamic characterization of the glass transition. In the vicinity of the glass transition, the mean-square displacement exhibits a non-t-linear behavior, sometimes called a subdiffusive behavior, and the incoherent scattering function is well fitted by "stretched exponential" function. The non-Gaussian parameter as a function of time has a large maximum, and the product of the maximum value and the corresponding time increases sharply as approaching the glass transition. All these anomalous characteristic properties are similar to those found for a binary soft-sphere fluid in our previous work, and in a good agreement with the predictions of the trapping diffusion theory. We discuss the validity of this theory.