Forecasting the experimental glass transition from short time relaxation data

Abstract

While molecular simulations have contributed to the modern understanding of the glass transition, they are constrained in prediction of experimental glass temperatures Tg because they are limited to times far shorter than those associated with experimental glass formation. Here, we bridge this gap via a model-based forecasting approach. We assess models of the temperature dependence of dynamics in glass forming liquids based upon the rate at which their prediction of Tg and fragility converge upon incorporating increasingly long timescale data. We find that the Cooperative Model of Schmidtke et al. typically provides the best predictions, ultimately enabling good Tg predictions from all-atom simulations of a range of polymers. Together with a protocol for efficient simulation of dynamics in glass-forming liquids, this strategy enables high-throughput computational screening of the glass transition. The success of the Cooperative Model in predicting low temperature behavior adds support to the two-barrier scenario underlying this model.