Efficient Treatment of the Effect of Vibrations on Electrical, Magnetic, and Spectroscopic Properties

Vibrational motions can play an important role in determining electrical, magnetic, and spectroscopic properties through so-called nuclear relaxation, zero-point vibrational averaging, or a combination of the two. Recent advances in the analysis and computational treatment of these phenomena include the finite field/nuclear relaxation technique and field-induced coordinates. These methodologies, which were originally developed for nonresonant electric dipole (hyper)polarizabilities, are reviewed and extended to magnetic properties as well as properties involving simultaneous electric and magnetic fields. In addition, spectroscopic applications such as two-photon absorption, circular dichroism, and infrared/Raman vibrational intensities are considered. With the finite field/nuclear relaxation technique and field-induced coordinates, computations are now feasible for much larger molecules than before.