In this work, we investigate the solvation of tetravalent thorium Th(IV) in aqueous solution using classical molecular dynamics simulations at the 10 ns scale and based on polarizable force-held approaches which treat explicitly the covalent character of the metal-water interaction (and its inherent cooperative character) We have carried out a thorough analysis of the accuracy of the ab initio data that we used to adjust the force-field parameters In particular, we show that large atomic basis sets combined with wave function-based methods (such as the MP2 level) have to be preferred to density functional theory when investigating Th(IV)/water aggregates in gas phase The information extracted from trajectories in solution shows a well-structured Th(IV) first hydration shell formed of 8 25 +/- 0 2 water molecules and located at about 2 45 +/- 0 02 angstrom and a second shell of 17 5 +/- 0 5 water molecules at about 4 75 angstrom Concerning the first hydration sphere, our results correspond to the lower bounds of experimental estimates (which range from 8 to 12 7), however, they are in very good agreement with the average of existing experimental data 2 45 +/- 0 02 angstrom All our results demonstrate the predictable character of the proposed approach as well as the need of accounting explicitly for the cooperative character of charge-transfer phenomena affecting the Th(IV)/water interaction to build up reliable and accurate force-field approaches devoted to such studies