Abstract In this paper we show how molecular dynamics simulation can improve comprehension of structure and dynamics of water solvent around heavy cations. In particular, metal-water radial distribution function obtained from molecular dynamics can be used into EXAFS equation to improve the experimental signal fitting. Here we show results on structure and dynamics of Co²⁺, that is a radiocontaminant cation in its isotopic form ⁶⁰Co, and lanthanoids(III) that are the chemical analogues of actinides(III) in aqueous solution.