Solvation of complex surfaces via molecular density functional theory

Area of Science:

• Computational Chemistry
• Materials Science
• Physical Chemistry

Background:

• Studying solvation at interfaces is crucial for understanding chemical processes.
• All-atom molecular simulations offer detailed insights but are computationally expensive.
• Developing efficient methods for solvation studies is an ongoing challenge.

Purpose of the Study:

• To introduce classical molecular density functional theory (DFT) as an efficient tool for studying solvation of complex surfaces by polar solvents.
• To compare the accuracy and computational cost of DFT with all-atom molecular simulations.
• To analyze surface-solvent interactions on a clay surface using DFT.

Main Methods:

• Employed classical molecular DFT within the homogeneous reference fluid approximation.
• Utilized an atomistically-resolved clay surface model (over a thousand atoms).
• Simulated solvation by a molecular dipolar solvent, analyzing electrostatic and non-electrostatic interactions using the Clay Force Field (CLAYFF).

Main Results:

• Molecular DFT accurately predicts structural, orientational, and energetic solvation properties.
• The method reduces computation time by two orders of magnitude compared to all-atom simulations.
• Solvent energetics and structure showed weak dependence on clay surface atomic charges, even for polar solvents.

Conclusions:

• Classical molecular DFT is a powerful and efficient implicit solvent method for complex interfaces.
• Findings suggest that detailed atomic charges of surfaces may have limited impact on polar solvent interactions.
• Results have implications for the development of more efficient and accurate force fields for surface-solvent interactions.