  We present a new, fully analytical point scattering model which can be
applied to arbitrary anisotropic magneto-electric dipole scatterers, including
split ring resonators (SRRs), chiral and anisotropic plasmonic scatterers. We
have taken proper account of reciprocity and radiation damping for electric and
magnetic scatterers with any general polarizability tensor. Specifically, we
show how reciprocity and energy balance puts constraints on the electrodynamic
responses arbitrary scatterers can have to light. Our theory sheds new light on
the magnitude of cross sections for scattering and extinction, and for instance
on the emergence of structural chirality in the optical response of
geometrically non-chiral scatterers like SRRs. We apply the model to SRRs and
discuss how to extract individual components of the polarizability matrix and
extinction cross sections. Finally, we show that our model describes well the
extinction of stereo-dimers of split rings, while providing new insights in the
underlying coupling mechanisms.
