Relativistic effects are often considered to be important largely for heavy elements. However, this is not the case for nuclear magnetic resonance (NMR) parameters. This is in part due to the fact that the nuclear magnetic shielding tensors and the indirect nuclear spin–spin coupling tensors are governed to a large extent by the electron density near the nucleus (outer core-inner valence electrons), but also due to the fact that magnetic interactions can be considered relativistic in nature.¹  The coupling between the electron spin and the orbital motion of the electrons through the spin–orbit operator allows for new interaction mechanisms...