Transverse thermal diffusion in an electric field for optically active systems

For systems which lack inversion symmetry the existence of transverse, odd-in-the-electric-field effects on transport properties cannot be excluded by spatial symmetry arguments alone. If, in addition, time reversal (Onsager) relations are invoked, transverse effects vanish in heat conduction and diffusion, but can still occur in thermal diffusion and the diffusion thermo (Dufour) effect. A theoretical treatment of transverse thermal diffusion for optically active systems in an electric field is given using a Chapman-Enskog method. The consistency of the kinetic theory with time reversal and spatial symmetry is shown.