Atomistic description of binary lanthanoid salt solutions: a coarse-graining approach

Area of Science:

• Solution chemistry
• Computational chemistry
• Materials science

Background:

• Lanthanoid and actinoid solution chemistry presents significant experimental challenges.
• Molecular dynamics (MD) simulations offer structural insights but are limited in scale for macroscopic properties.
• Existing models struggle to bridge microscopic simulations with experimentally measured macroscopic properties.

Purpose of the Study:

• To develop and validate a multiscale approach for studying lanthanoid-chloride aqueous solutions.
• To accurately predict thermodynamic and structural properties of these solutions.
• To bridge the gap between atomic-level simulations and macroscopic solution behavior.

Main Methods:

• Utilizing molecular dynamics (MD) simulations with explicit solvents to generate radial distribution functions (RDFs).
• Employing an inversion procedure with approximate hypernetted chain (HNC) closure and Stillinger-Lovett sum rules to derive effective ion-ion potentials from RDFs.
• Performing implicit solvent Monte Carlo (MC) simulations to calculate osmotic coefficients.

Main Results:

• Accurate effective pair potentials for lanthanoid salts were derived from an atomic model.
• The multiscale approach successfully computed osmotic coefficients for lanthanoid-chloride solutions.
• The method effectively links detailed structural information from MD to macroscopic thermodynamic properties.

Conclusions:

• The proposed multiscale strategy provides a robust method for modeling lanthanoid solution properties.
• This approach enhances the predictive power of simulations for complex ionic solutions.
• It offers a valuable tool for understanding and predicting the behavior of lanthanoid and actinoid solutions.