Full spectral decomposition of ring currents

The projection of perturbed orbitals onto the virtual orbital space allows partition of induced current density into contributions from individual virtual excitations between occupied and unoccupied orbitals, enabling the assignment of the origin of currents within the ipsocentric method for calculation of molecular magnetic response. The delocalized currents in benzene and planar cyclooctatetraene are described by transitions within the valence space and localized currents in the benzene [pi] system involve excitations outside the valence space.