Recent Advances in Nuclear Shielding Calculations

Nuclear magnetic shielding calculations have reached a great deal of sophistication as these now incorporate both relativistic and correlation effects. Approaches now include molecular dynamics as well as effects of the medium in condensed phases. With these computational tools, calculated shielding values are now obtained under conditions as close as possible to those of a sample inside a nuclear magnetic resonance spectrometer. Indeed, computations are approaching the limits of experimental uncertainty. A brief description of new methodologies of shielding calculations is presented followed by a review of the various factors that may influence shielding. The usefulness of being able to reproduce experimental data is highlighted by citing how shielding calculations in many instances have enabled avenues for extracting information on various systems.