Using metadynamics sampling to reach low energy states in a molecular glass

Metadynamics-based sampling has emerged as an advanced sampling method for accessing low energy configurations of simple model glasses¹. Here we report that this approach, called MIMSE, works effectively in a model molecular glass, α-α-Phen, which is not amendable to most advanced sampling techniques. This coarse grained molecular model was previously studied² using simulated physical vapor deposition (PVD), which also reached low energy configurations. Applying MIMSE to simulated bulk phases of α-α-Phen yields low energy states with significantly lower computational effort than simulated annealing, comparable to its performance in non-bonded model glasses such as Kob-Andersen. We will compare our low energy configurations in the bulk to the stable states obtained from PVD, and discuss the prospects for MIMSE as an advanced sampling method for reaching extremely low energies in bonded glass models.