Non-Equilibrium Modeling of Concentration-Driven processes with Constant Chemical Potential Molecular Dynamics...

Area of Science:

• Computational Chemistry
• Materials Science
• Physical Chemistry

Background:

• Concentration-driven processes like crystallization and adsorption are fundamental but challenging to simulate accurately due to finite-size effects in molecular dynamics (MD).
• Traditional MD methods struggle with solution depletion/enrichment in closed systems, altering the driving force for phenomena and limiting scale.

Purpose of the Study:

• To introduce and review the novel constant chemical potential molecular dynamics (CμMD) simulation technique.
• To illustrate the capabilities of CμMD in accurately characterizing concentration-driven phenomena.
• To assess the theoretical foundations, applications, and limitations of CμMD for in silico chemistry.

Main Methods:

• Development and application of constant chemical potential molecular dynamics (CμMD).
• CμMD utilizes concentration-dependent external forces to regulate solute flux between subregions, maintaining a constant chemical drive.
• Extension of CμMD to various physicochemical processes including crystallization, adsorption, permeation, and solution separation.

Main Results:

• CμMD enables accurate calculation of crystallization growth rates and equilibrium shapes.
• Adsorption thermodynamics on porous and solid surfaces are correctly characterized using CμMD.
• CμMD variants successfully simulate permeation, solution separation, and nucleation under fixed concentration gradients.

Conclusions:

• CμMD effectively overcomes finite-size limitations in molecular dynamics simulations of concentration-driven phenomena.
• The method provides new insights into diverse physicochemical processes previously limited by simulation scale.
• CμMD is a versatile and valuable tool for molecular-scale simulations of concentration-driven processes.