The investigation of ion association characteristics in lanthanum acetate solution using density functional theory and molecular dynamics simulations

Abstract

In this study, the structure and evolution of lanthanum acetate hydrated clusters were investigated using density functional theory (DFT) and molecular dynamics (MD) simulations to explore the influence of organic ammonium leaching agents on rare earth hydrated clusters at the microscopic level. Structural optimization, electrostatic potential (ESP) maps, and binding energies were calculated for La(CH₃COO)₃·nH₂O (n = 0–5) in the gas phase, and for La(CH₃COO)₃·nH₂O (n = 2–5) hydrated clusters using the PCM solvent model, all at the PBE0/6-311+G(d,p) level. Theoretical and experimental Raman spectra of lanthanum acetate were compared, which facilitated the determination of the hydrated cluster structure of lanthanum acetate. The findings revealed that the first hydration layer of the La acetate cluster reaches saturation when the number of water molecules is three, with the La(CH₃COO)₃·3H₂O cluster showing the lowest binding energy, indicating a stable structure. The results provide valuable insights into the structural characteristics and binding interactions within lanthanum acetate hydrated clusters, contributing to a better understanding of their behavior in solution.