The twisted arc model for chiral molecules

We present a simple model for chiral molecules which yields the frequency-dependent multipole-multipole polarizabilities required for calculating the dispersive van der Waals constants in a simple, closed, and consistent form. The model consists of a single effective charge confined to a one-dimensional wire formed by two circular arcs, which are twisted with respect to each other by an angle characterizing the chirality. The resulting polarizabilities show a simple functional dependence on the model parameters, and they serve to mimic the chiral properties of small molecules, such as H2S2, in a reasonably realistic way.