Table summarizes our single-point BS-DFT calculations, which reveal that the copper complex exhibits a strong antiferromagnetic coupling, whereas the nickel complex shows a coupling strength that is about half that of the copper complex and the iron complex displays an even weaker antiferromagnetic coupling. Experimental data for comparable complexes also show this pattern of a weakening antiferromagnetic coupling strength, with experimental J values ranging from -322 to -536 cm -1 for copper, -39 to -98 cm -1 for nickel, and -16 to -34 cm -1 for iron. Notably, functionals with similar Hartree-Fock (HF) exchange contributions, such as PBE0 and TPSS0 (both with 25% HF exchange), yield comparable results. In contrast, TPSSh with less HF exchange enhances the antiferromagnetic interactions. This pattern is consistent with what Kahn and Briat's model (eq. 3) predicts, which indicates a relationship between the quantity of the HF exchange and the ferromagnetic part of the J coupling.