Relativistic theory of indirect nuclear spin-spin coupling

A fully relativistic theory of indirect nuclear spin-spin coupling is presented that is based on the Green's function formalism. Implementation by the use of the multiple scattering or Korringa-Kohn-Rostoker (KKR) method leads to a very flexible and numerically efficient approach. Results obtained for fcc-Cu are found in full accordance with previous non- or scalar-relativistic calculations and show essentially the behaviour expected from Ruderman-Kittel theory for free-electron-like systems. Results for Ag and Au are represented, in addition, to demonstrate the impact of relativistic effects.