An implicit electrolyte model for plane wave density functional theory exhibiting nonlinear response and a nonlocal...

Area of Science:

• Computational chemistry
• Materials science
• Electrochemistry

Background:

• Implicit electrolyte models are crucial for simulating electrochemical interfaces.
• Existing models often lack accuracy in capturing nonlinear electrolyte behavior.
• Accurate modeling is needed for understanding and designing electrocatalytic processes.

Purpose of the Study:

• To implement and validate a novel implicit electrolyte model in VASP.
• To incorporate nonlinear dielectric and ionic responses with nonlocal cavity definitions.
• To enable routine computation of activation barriers for electrocatalysis.

Main Methods:

• Developed an implicit electrolyte model within the VASPsol code.
• Included nonlinear dielectric and ionic responses.
• Implemented nonlocal cavity definitions for spatial response regions.

Main Results:

• The model shows numerical efficiency and robust convergence.
• Successfully reproduced the experimental "double hump" differential capacitance.
• Prevented electrolyte "leakage" into unphysical regions.
• Provided reasonable predictions for solvation free energies and water self-ionization.

Conclusions:

• The new nonlinear + nonlocal model enhances VASPsol's capabilities for electrochemical simulations.
• It accurately captures interface phenomena and predicts key thermodynamic properties.
• Enables routine computation of electrocatalytic activation barriers using density functional theory.