Spin-orbit correction to NMR shielding constants from density functional theory

A new method based on density functional theory for the calculation of spin-orbit corrections to NMR shielding constants is presented. This approach provides the opportunity of calculating the relativistic spin-orbit correction, based on a DFT method which incorporates correlation effects and with the use of a special choice of gauge origin. The inclusion of the one-electron spin-orbit operator brings the results for 1H chemical shifts in HF, HCl, HBr and HI and 13C chemical shifts in halogenomethanes into good agreement with experiment. The calculated one-electron spin-orbit corrections depend strongly on the basis set quality.