A Gd-Dimer Benchmark Study: Is DFT an Accurate Method for the Prediction of Gadolinium Exchange Coupling Constants?

Gd(III)-Gd(III) exchange interactions are central to a number of applications, such as the magnetocaloric effect or single molecule magnetism. Broken-symmetry density functional theory is the most widely used computational technique for these calculations, yet no comprehensive benchmark has been established. Here, we present the computational analysis of 27 binuclear Gd(III) compounds in comparison to experimental data and propose a best-practice workflow. We encourage the explicit treatment of scalar relativistic effects and the use of a combination of hybrid functionals with different amounts of exact exchange. Furthermore, we investigated this testbed for structure-property relationships and demonstrated the use of the recommended methodology on two tetranuclear Gd(III) clusters.