Computational study of basis set and electron correlation effects on anapole magnetizabilities of chiral molecules

Abstract

In the presence of a static, nonhomogeneous magnetic field, represented by the axial vector B at the origin of the coordinate system and by the polar vector C=∇×B, assumed to be spatially uniform, the chiral molecules investigated in this paper carry an orbital electronic anapole, described by the polar vector A. The electronic interaction energy of these molecules in nonordered media is a cross term, coupling B and C via ā, one third of the trace of the anapole magnetizability aαβ tensor, that is, WBC=-āB·C. Both A and WBC have opposite sign in the two enantiomeric forms, a fact quite remarkable from the conceptual point of view. The magnitude of ā predicted in the present computational investigation for five chiral molecules is very small and significantly biased by electron correlation contributions, estimated at the density functional level via three different functionals.