Efficient and accurate solvation energy calculation from polarizable continuum models.

Area of Science:

• Computational chemistry
• Theoretical chemistry
• Molecular modeling

Background:

• Implicit solvation models like PCM represent solvent effects using apparent charges on a molecular cavity surface.
• Increasing surface tessellation improves accuracy but significantly increases computational cost.
• Existing methods struggle with accurate self-contribution calculations of apparent charges.

Purpose of the Study:

• To develop a novel approach for enhancing the efficiency and accuracy of electrostatic interaction calculations in implicit solvation models.
• To address the trade-off between accuracy and computational time in polarizable continuum model (PCM) variants.
• To minimize errors in solvation free energy calculations, particularly for ions and complex molecules.

Main Methods:

• The proposed method refines the treatment of apparent charge self-contributions by considering segment size and curvature.
• A multiple-sampling technique is introduced for molecules with non-uniform apparent charge density gradients.
• The approach aims to decouple accuracy from the degree of surface tessellation.

Main Results:

• The refined self-contribution treatment leads to essentially zero error in electrostatic solvation free energy for ions.
• The multiple-sampling technique significantly reduces calculated errors for molecules compared to original PCM methods.
• The new approach demonstrates improved accuracy and efficiency, especially with limited tessellation.

Conclusions:

• The proposed method effectively resolves the accuracy-efficiency dependency in PCM-based solvation models.
• Accurate treatment of apparent charge self-contributions is crucial for reliable electrostatic solvation energy calculations.
• This work offers a more computationally feasible and accurate way to model solvent effects in molecular simulations.