Hybrid explicit-droplet/implicit solvation model to accelerate constant-potential molecular dynamics simulations.

Area of Science:

• Computational chemistry
• Materials science
• Electrochemistry

Background:

• Hybrid solvation models are crucial for simulating electrochemical solid-liquid interfaces.
• Current models face high computational costs and solvent dissolution issues.

Purpose of the Study:

• To develop an efficient hybrid explicit-droplet/implicit solvation model for constant-potential molecular dynamics.
• To overcome computational limitations of existing solvation models.

Main Methods:

• Implemented a hybrid explicit-droplet/implicit solvation model in VASPsol++.
• Utilized algorithms to exclude implicit solvent and prevent explicit solvent dissolution.
• Integrated continuous cavity and radius/density-constant implementations.

Main Results:

• The droplet approach accurately reproduced interfacial properties like electron-count fluctuations and free-energy barriers.
• Validated results with Co-N-C motifs and MoS2 edge systems.
• Achieved 2-4 times acceleration in barrier-calculation speed.

Conclusions:

• The developed model offers a significant acceleration for simulating electrochemical interfaces.
• Provides a more accessible and reliable tool for constant-potential molecular dynamics studies.
• Enables efficient simulations around local reactive sites.