Excited States and Photochemistry

Abstract

The treatment of electronically excited states of molecules and clusters is by far the most common application of time-dependent density functional theory (TDDFT) in chemistry. TDDFT calculations are increasingly used by non-experts to support and interpret experimental results. Important reasons for the success of TDDFT in photochemistry are its cost/performance ratio which is unmatched by traditional methods and the relatively wide applicability range. In this chapter we briefly survey the technology which underlies these applications. We discuss what accuracy can be expected for excited state properties with contemporary functionals, and where they fail. Finally, we present an up-to-date survey of TDDFT applications in photochemistry. Since the literature is growing rapidly, we limit ourselves to exemplary work and “hot” topics. Strong fields, applications to molecular dynamics, and the optical response of clusters, extended systems, and biochromophores are treated in Chaps. 22–26, 27, 17–18, 20–21, and 22, respectively. The present work complements and extends earlier reviews [Furche 2005a, Furche 2005c].