Computation of solid-fluid interfacial free energy in molecular systems using thermodynamic integration

Area of Science:

• Computational chemistry
• Materials science
• Chemical engineering

Background:

• Solid-fluid interfacial free energy is crucial for understanding crystallization.
• Predicting crystal polymorph selectivity is vital in pharmaceutical and materials development.
• Molecular simulations offer a powerful tool for investigating interfacial phenomena.

Purpose of the Study:

• To present two thermodynamic integration methods for calculating solid-fluid interfacial free energy.
• To apply these methods to orcinol crystal polymorphs interacting with chloroform and nitromethane.
• To use computed interfacial free energies to predict solvent-induced polymorph selectivity via classical nucleation theory.

Main Methods:

• Thermodynamic integration was employed to compute solid-fluid interfacial free energy.
• Two crystal polymorphs of orcinol served as the solid phase.
• Chloroform and nitromethane were used as the liquid phases.

Main Results:

• Interfacial free energy values were successfully computed for the orcinol-solvent systems.
• The computed values were integrated with classical nucleation theory.
• Predictions of solvent-induced polymorph selectivity were made based on the calculations.

Conclusions:

• The developed thermodynamic integration methods are effective for determining solid-fluid interfacial free energy.
• The study demonstrates the utility of these calculations in predicting crystallization behavior.
• This approach provides insights into controlling polymorph selection through solvent choice.