Related Experiment Video
Updated: Jul 4, 2026
13:21
Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
Stability constants of lanthanide-nitrate complexes in aqueous solutions: a theoretical study
Mohammadhasan Dinpajooh1, Niranjan Govind1,2, Andrew M Ritzmann3
1Physical & Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA. hadi.dinpajooh@pnnl.gov.
Physical Chemistry Chemical Physics : PCCP
|July 3, 2026
Summary
Calculating lanthanide-nitrate complex stability constants is difficult. Cluster-continuum solvation offers a semi-quantitative baseline, while machine learning interatomic potentials (MLIPs) show progress but require further development for accurate aqueous lanthanide chemistry.
Area of Science:
- Computational chemistry
- Solution chemistry
- Lanthanide chemistry
Background:
- Calculating stability constants for lanthanide-nitrate complexes in aqueous solution presents significant challenges due to complex free-energy landscapes.
- Accurate thermodynamic data is crucial for understanding and predicting lanthanide behavior in various chemical and biological systems.
Purpose of the Study:
- To compare cluster-continuum solvation and condensed-phase approaches using machine learning interatomic potentials (MLIPs) for determining lanthanide-nitrate complex stability constants.
- To evaluate the accuracy and limitations of different computational methods in modeling aqueous lanthanide chemistry.
Main Methods:
- Density functional theory (DFT) with B3LYP level for cluster-continuum solvation.
- Universal machine learning interatomic potentials (MLIPs), including MACE-MP0 and MACE-MATPES-R2SCAN, for condensed-phase simulations.
- Analysis of coordination numbers, free-energy corrections, hydration structures, and potential of mean forces.
Main Results:
- Cluster-continuum solvation, after empirical correction, provides results on the same order of magnitude as experimental stability constants.
- MACE-MP0 MLIP underestimates hydration numbers and yields large deviations in stability constants.
- MACE-MATPES-R2SCAN improves hydration structure and stability constant scale but does not fully capture the lanthanide trend.
- Nitrate binding is characterized as labile, with interconverting mono- or bidentate structures influenced by hydration-shell structure.
Conclusions:
- Cluster-continuum calculations offer a practical semi-quantitative baseline for experimental stability constants.
- Explicit-solvent MLIP benchmarks demonstrate progress but indicate a need for lanthanide-specific training or improved treatments for predictive thermodynamics.
- Further advancements in MLIPs are necessary for accurately modeling complex aqueous lanthanide chemistry.
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