Abstract : This is essentially a lanthanide trication hydration study by means of classical molecular dynamics (CLMD) simulations using explicit polarization. Explicit polarization is calculated with a Car-Parrinello type of dynamics on induced dipoles, which decreases the CPU time as compared to the self-consistent resolution. Several pair interaction potentials are parametrized from ab initio calculations (MP2) and tested for the La3+/OH2 interaction. The best results are obtained with an exponential-6 Buckingham potential. Next, the La3+/OH2 interaction potential parameters are extrapolated to the other Ln3+/OH2 interactions, only by using the ionic radii. The CLMD results reproduce the reliable experimental data (EXAFS distances), and the sigmoidal variation of the coordination number (with S shape), from 9 for La3+ to 8 for Lu3+. This variation is explained by the linear variation of DrG0 (9,298) vs. atomic number. Insights are also given on the Co2+ hydration, CPMD simulations,
reconstruction of EXAFS signal from MD simulations, and OH− complexation of La3+ in aqueous solution.