Theory and computation of nuclear shielding

Abstract

This chapter continues earlier reviews of essential works on theoretical issues of nuclear magnetic shieldings published from 1 January to 31 December 2022. As previously, the chapter concentrates on theoretical calculations of nuclear shielding parameters and/or chemical shifts in case of free molecules in the gas phase and solution, and in some cases in the solid state using a periodic formulation. The nuclear shieldings in solution are mainly calculated using inexpensive polarizable continuum model of solvent (PCM). The use of discrete solvent molecules (in particular water and other polar solvents), which is essential for correct description of hydrogen bonding, is often omitted by numerous authors. Most calculations use a relatively simple and fast, but reliable density functional theory (DFT) combined with gauge-including atomic orbital (GIAO) approach. On the other hand, reports on prediction of nuclear magnetic shielding parameters using high level theoretical methods combined with large and flexible basis sets are not so common due to the enormous computational cost. In addition, correction of raw theoretical nuclear magnetic shieldings due to ro-vibration (zero-point vibration correction, ZPVC) and temperature corrections (TC), as well as implicit and explicit solvent effects and relativistic corrections are not often reported.