Benchmarking Density Functional Approximations for Diamagnetic and Paramagnetic Molecules in Nonuniform Magnetic Fields

In this article, correlated studies on a test set of 36 small molecules are carried out with both wavefunction (HF, MP2, CCSD) and density functional (LDA, KT3, cTPSS, cM06-L) methods. The effect of correlation on exotic response properties such as molecular electronic anapole susceptibilities is studied and the performance of the various density functional approximations are benchmarked against CCSD and/or MP2. Atoms and molecules are traditionally classified into diamagnetic and paramagnetic based on their isotropic response to uniform magnetic fields. However, in this article, we propose a more fine-grained classification of molecular systems on the basis of their response to generally nonuniform magnetic fields. The relation of orientation to different qualitative responses is also considered.

Automated summary

This article explores correlated studies on a test set of 36 small molecules using both wavefunction and density functional methods. The research focuses on the effect of correlation on exotic response properties and benchmarks the performance of density functional approximations against CCSD and/or MP2. A more detailed classification of molecular systems based on their response to generally nonuniform magnetic fields is proposed, with consideration given to the relation of orientation to different qualitative responses.