Ab initio modeling of volume–temperature curves for glassforming systems

We derive a new model of the glass transition for isobaric conditions. Our model is based on mapping the continuous (3N + 1)-dimensional enthalpy landscape of a glassforming system to a discrete set of inherent structure and transition point enthalpies. Using a master equation approach, we follow the time evolution of a system from its equilibrium liquid state through an arbitrary cooling path. Our model employs a phase space distribution matrix to enable computation of macroscopic properties as a function of time. We have implemented our model for selenium and present the first-ever volume–temperature curves of a glassforming system based solely on ab initio physics.