Since classical molecular dynamics have also been used extensively to investigate the solutesolvent interaction of solutions of transition metal complexes, we examine here the PECs obtained with CHELPG partial charges of the complex, OPLS LJ parameters, using the TIP4PEW potential for water, and compare the results against those of the reference. As shown in Figure and table 1, the OPLS/TIP4PEW method slightly overestimates R e by 0.2 Å with respect to the DLPNO-CCSD(T) value. Moreover, although the trend of the HS-LS energy difference is in accordance with the reference, the OPLS/TIP4PEW potential is very repulsive at short Fe-O distance. For instance, for the LS state, OPLS/TIP4PEW calculations show that the repulsive interaction already dominates at distances of 3.9 Å and 4.8 Å for a water molecule in pose A and B, respectively, distances for which the DLPNO-CCSD(T) interactions are still binding, i.e., -0.147 eV and -0.273 eV.