Self-Diffusion and Glass Transition of the Soft-Core Model

Abstract

The soft-core model with the inverse power potential ¢(r) =E(CJ/r)n, has been studied as a simple, but realistic model for actual simple liquids like argonY -3 ) With the molecular dynamics calculations the self-diffusion coefficient of the model has been presented by our previous paper 3 l and by Ross and Schofield, <l over a wide range of the reduced density p*=pa 3 (c/kT) 3 1n including supercooled states, where

Computer Simulations of Freezing and Supercooled Liquids

“…35 (kT/e) 1/4 as the glass transition density. However, subsequent analysis (111), revealed that the diffusion constant at high densities fits well an equation of the form…”

“…Several authors have studied the amorphous phase of continuous potential systems, in particular the 3-D Lennard-Jones system (88,96,(104)(105)(106)(107)(108)(109)(110), the soft-core system (66,111), and the Gaussian system (112). It should be noted that in all these systems crystal nucleation has also been observed.…”

“…The metastable branch of the soft-core fluid has been studied by Hiwatari et al (66,111). It was observed that the diffusion constant the metastable soft-core fluid becomes unobservably small for densities higher than p,~_,l.35(kT/e) 1/4 or, equivalently, T*=0.63T~.…”