Deriving reliable nucleation rates from metadynamics simulations: Application to Yukawa fluids

Area of Science:

• Computational physics
• Materials science
• Chemical physics

Background:

• Classical nucleation theory (CNT) is a foundational model for understanding phase transitions.
• Metadynamics is a powerful simulation technique for exploring free energy landscapes.
• Accurately calculating nucleation free energy barriers is crucial for predicting crystallization rates.

Purpose of the Study:

• To establish a robust procedure for calculating nucleation free energy barriers using metadynamics.
• To highlight the advantages of local collective variables over global ones in metadynamics simulations.
• To demonstrate the application of this procedure for predicting nucleation rates in supercooled liquids.

Main Methods:

• A pedagogical review of classical nucleation theory and metadynamics principles.
• Detailed explanation of local versus global collective variables in metadynamics.
• A post-processing method to apply CNT to metadynamics-derived free energy barriers.
• Application of the procedure to a Yukawa plasma system.

Main Results:

• A specific procedure for calculating nucleation free energy barriers with metadynamics is provided.
• Local collective variables are shown to be beneficial for metadynamics studies of nucleation.
• Post-processing metadynamics data enables accurate application of CNT for nucleation rate calculations.
• The developed method successfully reproduced low-temperature reference data for a Yukawa plasma.

Conclusions:

• Metadynamics, when combined with careful post-processing, is a valuable tool for studying crystal nucleation.
• The proposed procedure solidifies the usefulness of metadynamics for predicting nucleation rates.
• This work provides a pathway for more accurate computational predictions of crystallization phenomena.