Solv: An Alternative Continuum Model Implementation Based on Fixed Atomic Charges, Scaled Particle Theory, and the...

Area of Science:

• Computational chemistry
• Physical chemistry
• Theoretical chemistry

Background:

• Continuum models are essential for predicting solvation free energies.
• Accurate electrostatic and non-electrostatic interactions are crucial for model performance.
• Existing models require refinement for diverse chemical systems and solvents.

Purpose of the Study:

• To develop and validate an alternative continuum model for solvation free energy calculations.
• To assess the performance of different approaches for calculating non-electrostatic contributions.
• To identify the optimal model parameters for nonaqueous solvent systems.

Main Methods:

• Implementation of a noniterative conductor-like screening model for electrostatic energy.
• Calculation of nonelectrostatic dispersion-repulsion energy using the Caillet-Claverie method.
• Computation of nonelectrostatic cavitation energy via scaled particle theory (SPT) with solute radii from Pierotti-Claverie (PC) schemes (SPT-S, SPT-V).
• Fitting solvent hard-sphere radius to experimental data for 2530 neutral species in 92 solvents.

Main Results:

• The model successfully reproduces absolute and relative solvation free energies.
• The SPT-V approach, utilizing CM5 charges, demonstrated superior performance.
• The optimized solvent hard-sphere radius improved accuracy across various systems.

Conclusions:

• The developed continuum model provides a robust method for solvation free energy prediction.
• The SPT-V approach combined with CM5 charges is recommended for nonaqueous solvents.
• This model offers a valuable tool for computational studies in physical and computational chemistry.