From microhydration to bulk hydration of Sr2+ metal ion: DFT, MP2 and molecular dynamics study

► We report the structure and energetics of hydrated cluster of Sr2+(H2O)n (n = 1-24) at DFT and MP2 level of theories. ► MD simulation was conducted to predict the CN and EXAFS spectra. ► The quantum results suggest a CN of 8 for the first hydration shell of Sr2+, in agreement with XAFS. ► The theoretical Sr2+-O bond distance is in excellent agreement with the EXAFS data. ► MD-EXAFS and CN analysis reveals that the TIP4P-2005 model is superior water model in predicting EXAFS spectra.