Hi All, We have a group meeting with Professor George Schatz from 4-530 at the theory couches. His abstract is below. I hope to see you all there. Best, Thomas Plasmon-molecule interactions George C. Schatz Northwestern University, Evanston IL 60208-3113 USA               This talk describes recent theory developments concerned with the optical properties of plasmonic materials, with emphasis on understanding plasmon enhanced spectroscopic techniques such as surface enhanced Raman spectroscopy (SERS), plasmon-enhanced photochemistry, and the coupling of plasmons to excitons.  The cornerstone of this work is computational electromagnetics, which provides the ability to solve Maxwell’s equations exactly for a given nanoparticle structure and with assumed dielectric functions. A number of methods for doing these calculations are available, and in the first part of the talk I will review how these calculations are done, and I will demonstrate their use to study the extinction spectra and SERS of silver and gold nanoparticles and other nanostructures. In addition, I will describe very recent applications concerned with the optical properties of nanoparticle superlattices that constitute a type of metamaterial that exhibits unusual optical properties.   The second half of the talk will focus on problems where one needs to couple classical electrodynamics for metal particles to quantum mechanics (usually TDDFT) for molecules near the nanoparticles. These theories will be developed both in the frequency and time domains, and the inclusion of both electromagnetic interactions and chemical interactions between the metal nanoparticle and molecular adsorbate are considered. We demonstrate the use of these methods with applications to SERS and to plasmonic solar cells.  In addition, we describe examples of plasmon-exciton interactions, such as occurs in plasmon-enhanced lasing. Here we show how plasmons can interact with molecules to enhance both spontaneous and stimulated emission.