RESPONSE FUNCTION-ANALYSIS OF MAGNETIC OPTICAL-ROTATION

The Verdet constant describing magnetic optical rotation (MOR) in atom s and molecules is analyzed in terms of polarization propagators. The effect, rotation of the plane of polarization of Light by a perturbing magnetic field, is modeled through quadratic response functions (QRFs ). For atomic systems, we prove that the standard third-order MOR expr ession simplifies to the Becquerel dispersion formulation, also known as the normal Verdet constant. This is shown to arise naturally from Q RFs under spherical symmetry. A general proof is also offered for the gauge origin invariance of third-order expressions in systems possessi ng an inversion center. Finally, methods for assessing the completenes s of basis-set representation with respect to MOR calculations are dis cussed. (C) 1997 John Wiley & Sons, Inc.