Free-energy reconstruction from stable clusters (FRESC): A new method to evaluate nucleation barriers from simulation

Area of Science:

• Physical Chemistry
• Computational Science

Background:

• Nucleation processes are fundamental in physical chemistry.
• Accurately determining the nucleation barrier (free energy of critical cluster formation) is essential but challenging.
• Existing methods often rely on classical nucleation theory or complex simulation setups.

Purpose of the Study:

• To present a novel, efficient simulation technique for calculating the nucleation barrier.
• To overcome limitations of current methods for simulating nucleation.
• To enable simulations of nucleation in complex systems.

Main Methods:

• Simulating a small, stabilized cluster in the NVT ensemble.
• Applying the thermodynamics of small systems to derive the Gibbs free energy of formation.
• Validating the method using condensation in a Lennard-Jones fluid.

Main Results:

• The new method accurately calculates the nucleation barrier.
• Demonstrated excellent agreement with established umbrella sampling simulations.
• The technique requires fewer particles and no predefined reaction coordinates.

Conclusions:

• This simulation approach offers a straightforward and computationally inexpensive way to determine nucleation barriers.
• It eliminates the need for classical nucleation theory and complex cluster definitions.
• The method holds potential for simulating nucleation in industrially relevant complex molecules.