Basis set error estimation for DFT calculations of electronic g-tensors for transition metal complexes

We present a detailed study of the basis set dependence of electronic g‐tensors for transition metal complexes calculated using Kohn–Sham density functional theory. Focus is on the use of locally dense basis set schemes where the metal is treated using either the same or a more flexible basis set than used for the ligand sphere. The performance of all basis set schemes is compared to the extrapolated complete basis set limit results. Furthermore, we test the performance of the aug‐cc‐pVTZ‐J basis set developed for calculations of NMR spin‐spin and electron paramagnetic resonance hyperfine coupling constants. Our results show that reasonable results can be obtain when using small basis sets for the ligand sphere, and very accurate results are obtained when an aug‐cc‐pVTZ basis set or similar is used for all atoms in the complex. © 2014 Wiley Periodicals, Inc. The calculation of the electronic g‐tensor for electron paramagnetic resonance (EPR) is a promising route to aid experimental investigations, especially within bio‐inorganic chemistry. However, as the number of basis functions greatly increase for compounds containing d‐block elements, it would be desirable if a smaller basis set could be used for the ligands in a so‐called locally dense basis set approach. This article reports the accuracy of several locally dense basis set schemes and compares these to an extrapolated complete basis set value.