Solvation free-energy pressure corrections in the three dimensional reference interaction site model

Area of Science:

• Computational chemistry
• Physical chemistry

Background:

• Solvation free energies are crucial in chemistry.
• Molecular density functional theory (DFT) predictions are improved by correcting overpressure from homogeneous reference fluid approximations.
• Previous work introduced pressure correction (PC) and advanced pressure correction (PC+) methods.

Purpose of the Study:

• To rigorously derive the pressure expression within the 3D-RISM framework.
• To provide a consistent method for applying PC and PC+ corrections to 3D-RISM solvation free energy calculations.

Main Methods:

• Derivation of pressure expression in 3D-RISM.
• Application and analysis of PC and PC+ corrections within 3D-RISM.

Main Results:

• Rigorous derivation of pressure, PC, and PC+ expressions for 3D-RISM.
• Demonstration that PC and PC+ significantly improve 3D-RISM predictions.
• Identification of PC+ as potentially decreasing accuracy in some contexts.

Conclusions:

• The derived expressions offer a consistent approach for correcting 3D-RISM solvation free energies.
• This work refines the application of pressure corrections in molecular simulations.
• Accurate prediction of solvation free energies is enhanced through rigorous theoretical treatment.