Electrodynamics in computational chemistry

This chapter gives a synoptic view on the interaction of light with particles that are sufficiently large in size that classical electrodynamics can be used to describe the optical properties of the particle. Most of the review is concerned with metal nanoparticles (silver and gold), where the linear optical properties (extinction, absorption, and scattering) are strongly dependent on particle size, shape, and local dielectric environment. To describe such problems, there has been much recent progress in the use of computational electrodynamics methods including the discrete dipole approximation, the finite difference time domain method, and other methods, and one can review recent applications of these methods that have been used to interpret the experiments. The chapter describes the development of electronic structure methods for describing the Raman spectra of molecules adsorbed on the surface of the metal particles, including methods that explicitly include the electric fields from classical electrodynamics calculations in the calculation of Raman intensities.