eq for all the stepwise association reactions due to the tendency of ions to associate in water at high temperatures. In general, the calculated values of log K ∞ eq for PIM are lower than those for N-POL MD for all association reactions at subcritical and supercritical conditions. This is because of the deep energy basins predicted by N-POL MD for CIPs, which make them more exothermic than those from PIM. Both models show an increase in log K ∞ eq The new PIM potential predicts La-Cl bond distances closer to AIMD data compared to N-POL are shorter than the 2.90-3.02 Å range predicted by experiments at similar conditions . Shorter bond lengths from PIM are a consequence of shorter bond lengths predicted by DFT which is used to generate the training configurations. Both models predict a decrease in La-Cl bond length with increasing temperature, which is consistent with experiments and AIMD at similar conditions.