Numerical method for computing the free energy of glasses.

Area of Science:

• Materials Science
• Computational Chemistry
• Statistical Mechanics

Background:

• Calculating equilibrium free energy is crucial for understanding glass properties.
• Standard extrapolation methods fail for glasses not prepared quasireversibly.
• Inherent structures (local energy minima) dominate glass behavior.

Purpose of the Study:

• To develop a novel numerical technique for computing equilibrium free energy in glasses.
• To address limitations of existing methods for non-quasireversibly prepared glasses.
• To enable accurate property estimation for ultrastable glassy materials.

Main Methods:

• Sampling the equilibrium partition function of inherent structure basins of attraction.
• Utilizing a procedure applicable to the supercooled liquid phase.
• Applying the method to a Kob-Andersen glass model.

Main Results:

• The proposed method provides lower free energy estimates than slow cooling.
• Estimates remain lower even at temperatures significantly below the glass transition.
• The technique successfully computes free energy for challenging glass systems.

Conclusions:

• The new numerical technique accurately computes equilibrium free energy for glasses.
• This method can be extended to calculate chemical potential and solubility of ultrastable glasses.
• The approach offers a rigorous way to study glass thermodynamics.