Insights into the mobility of rare earth complexes in groundwater-rock interactions: A geochemical view from modeling of computational chemistry
Por:
Castro-Ocampo O., Santos-Raga G., Santoyo E., Guerrero F.J., Delesma C., Muñiz J.
Publicada:
1 ene 2025
Resumen:
This study investigates the prediction and stability of novel complexes of rare earth elements (REE) under simulated groundwater and hydrothermal conditions. The electronic structure properties of the REE complexes LnX3 and Ln2Y3, with Ln = La, Lu; X = Cl-, F-, (HCO3)-, (AlO2)-, and Y = (SO4)2-, (CO3)2- were explored using density functional theory (DFT) including relativistic effects. The nature of the bonding in the complexes was assessed via the theory of atoms in molecules. Evidence shows that relativistic contributions play a significant role in stabilization energy and bonding distance, especially in La-complexes, where bond distances shrink by 0.64–6.82 %. Formation energies were calculated to identify the most stable configurations, being the most stable Ln2 (SO4)3. Molecular electrostatic potential (MEP) was analyzed to predict the acidic or basic behavior of the complexes. Ab initio molecular dynamics (AIMD) simulations were also performed for models with the first solvation shell, and also for models representing massive systems. In large-scale systems at 300 °C, the stability varies by element. For La, the most stable is La2(CO3)3, while for Lu, it is Lu2(SO4)3 ˜ Lu2(CO3)3. It evidences the feasibility of the existence of the REE complexes in aqueous media. These results give insight into the mobility and stability that these complexes may present in water-rock interaction processes of groundwater and environmental systems. © 2025
Filiaciones:
Castro-Ocampo O.:
Instituto de Energías Renovables, Universidad Nacional Autónoma de México, Priv. Xochicalco s/n, Col. Centro, Morelos, Temixco, CP 62580, Mexico
Santos-Raga G.:
Instituto de Energías Renovables, Universidad Nacional Autónoma de México, Priv. Xochicalco s/n, Col. Centro, Morelos, Temixco, CP 62580, Mexico
Santoyo E.:
Instituto de Energías Renovables, Universidad Nacional Autónoma de México, Priv. Xochicalco s/n, Col. Centro, Morelos, Temixco, CP 62580, Mexico
Guerrero F.J.:
Instituto de Energías Renovables, Universidad Nacional Autónoma de México, Priv. Xochicalco s/n, Col. Centro, Morelos, Temixco, CP 62580, Mexico
Delesma C.:
Departamento de Materiales de Baja Dimensionalidad, Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n Ciudad Universitaria, Apartado Postal 70-360, Ciudad de México, 04510, Mexico
Muñiz J.:
Instituto de Energías Renovables, Universidad Nacional Autónoma de México, Priv. Xochicalco s/n, Col. Centro, Morelos, Temixco, CP 62580, Mexico
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