Modelling uranyl chemistry in liquid ammonia from density functional theory.

Area of Science:

• Computational chemistry
• Theoretical chemistry
• Quantum chemistry

Background:

• Uranyl complexation reactions are crucial in nuclear fuel cycles and environmental remediation.
• Accurate prediction of reaction free energies is essential for understanding and optimizing these processes.
• Computational methods offer a powerful tool for studying complex chemical systems.

Purpose of the Study:

• To develop and validate a computationally efficient protocol for predicting uranyl complexation reaction free energies.
• To assess the performance of various Density Functional Theory (DFT) functionals.
• To evaluate different continuum solvation models (CSMs) against explicit solvent simulations.

Main Methods:

• Utilized Density Functional Theory (DFT) combined with a continuum solvation model (CSM).
• Tested multiple DFT functionals against coupled cluster with single, double, and perturbative triple excitations (CCSD(T)) benchmarks.
• Assessed various CSMs by comparing with Car-Parrinello Molecular Dynamics (CPMD) simulations in explicit solvent.

Main Results:

• The developed DFT-CSM protocol provides a computationally efficient means to predict reaction free energies.
• Performance of different functionals and CSMs was systematically evaluated.
• The study establishes a reliable computational approach for uranyl chemistry in liquid ammonia.

Conclusions:

• The computationally efficient DFT-CSM protocol is suitable for predicting uranyl complexation energies in liquid ammonia.
• This method can guide experimental studies and aid in the design of processes involving uranyl.
• The findings contribute to the advancement of theoretical methods in actinide chemistry.