A. T. Ta, A. Daouli, R. S. Ullberg, E. Fonseca, V. Proust, A. Grandjean, R. G. Hennig H.-C. zur Loye, M. Badawi and S. R. Phillpot, Physical Chemistry Chemical Physics 26, 14561 (2024). DOI: https://doi.org/10.1039/D4CP00467A

Zeolites are versatile materials renowned for their extra-framework cation exchange capabilities, with
applications spanning diverse fields, including nuclear waste treatment. While detailed experimental
characterization offers valuable insight, density functional theory (DFT) proves particularly adept at
investigating ion exchange in zeolites, owing to its atomic and electronic resolution. However, the
prevalent occurrence of zeolitic ion exchange in aqueous environments poses a challenge to
conventional DFT modeling, traditionally conducted in a vacuum. This study seeks to enhance zeolite
modeling by systematically evaluating predictive differences across varying degrees of aqueous solvent
inclusion. Specifically focusing on monovalent cation exchange in Na-X zeolites, we explore diverse
modeling approaches. These range from simple dehydrated systems (representing bare reference states
in vacuum) to more sophisticated models that incorporate aqueous solvent effects through explicit
water molecules and/or a dielectric medium. Through comparative analysis of DFT and semi-empirical
DFT approaches, along with their validation against experimental results, our findings underscore the
necessity to concurrently consider explicit and implicit solvent effects for accurate prediction of zeolitic
ionic exchange.