Born–Kuhn coupled oscillator model for optical activity in ordered media

Considering the phenomenological electromagnetic description of optical activity, we establish a unified formal framework, wherein the gyration and permittivity tensors of any ordered medium (a molecule or a crystal) can be derived using the classic Born–Kuhn coupled oscillator model. This model allows for efficient parameterisation of both tensors in terms of configurational and structural parameters (orientations, positions and coupling strengths) of a system of coupled oscillators having the same symmetries as the medium of interest. Thus, Born–Kuhn molecular models of all optically active crystal classes are established.