Unveiling the Performance of SCAN Functional for Studying the Hydrated Ion in Solution: A Hybrid Forces Molecular Dynamics Study of La3+ Hydration

SCAN/molecular mechanics molecular dynamics (SCAN/MM MD) simulations have been employed to investigate the structural and dynamical properties of La³⁺ in aqueous solution. These simulations revealed the presence of two distinct hydration shells, with the first shell exhibiting a La-O bond distance of 2.56 Å. The water molecules in this initial hydration shell displayed a mean residence time (MRT) of 208 ps, suggesting a less rigid structure. Five successful ligand exchange events occurred within a simulation duration of 100 ps. The stretching frequency of La-O was found to be 331 cm⁻¹, with a force constant of 92 N/m. Notably, the data obtained from the SCAN/MM MD simulation demonstrated good agreement with experimental findings.