  In this paper, 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 paper we propose a more
fine-grained classification of molecular systems on the basis of their response
to generally non-uniform magnetic fields. The relation of orientation to
different qualitative responses is also considered.
