Without any long-range dispersion correction, the agreement of the DFT potential energy curve to that of the DLPNO-CCSD(T) reference improves as one climbs the Jacob's ladder. For instance, the LS state calculations in pose A reveal that from BLYP to B3LYP to B2PLYP, the R e reduces from 6.0 Å to 5.8 Å to 4.9 Å (the reference value is 4.6 Å), which corresponds to the reduction of V min from -0.169 eV to -0.176 eV to -0.209 eV (the reference value is -0.281 eV). The agreement worsens at shorter Fe-O distances of, again, 3.65 Å where BLYP, B3LYP, and B2PLYP calculations result in repulsive interaction energy of 0.392 eV, 0.327 eV, and 0.186 eV, respectively (the reference value is 0.058 eV). The hardest barrier is found in BLYP without long range dispersion corrections.