Comparative analysis of surface phase diagrams in aqueous environment: Implicit vs explicit solvation models

Area of Science:

• Computational materials science
• Surface chemistry
• Electrochemistry

Background:

• Understanding solid/water interfaces is crucial for reaction mechanisms.
• Surface phase diagrams predict stable surface structures under electrochemical conditions.

Purpose of the Study:

• Compare implicit and explicit solvent models for surface energy and phase diagram calculations.
• Evaluate the accuracy and efficiency of implicit solvent models for the magnesium/water interface.

Main Methods:

• Systematic comparison of implicit and explicit solvent approaches.
• Modeling the magnesium/water interface with Ca substitution and ion adsorption.
• Analysis of surface energies and phase diagrams.

Main Results:

• Implicit solvent models are computationally efficient but sensitive to parameter choices.
• Default parameters can lead to inaccurate surface energetics and spontaneous dissolution.
• Implicit models may yield metastable configurations for charged surfaces and solvated ions.
• Adjusted implicit models closely match explicit solvent results.

Conclusions:

• Implicit solvent models can be accurate surrogates for explicit models when properly parameterized.
• Addressing parameter sensitivity and charge state convergence is key for reliable implicit solvent calculations.
• Optimized implicit solvent models provide a computationally efficient tool for studying surface phase diagrams.