Time-dependent density-functional calculations for the optical spectra of molecules, clusters, and nanocrystals

In this review, we will describe calculations using time-dependent density-functional theory (DFT) combined with pseudopotentials to determine excited state properties of matter. While a computational framework for ground state properties of condensed matter is well established, calculations for excited state properties are at a more formative stage. Time-dependent DFT represents an important advance by providing an explicit treatment of relevant correlation effects for electronic excitations. As such, it offers an ab initio formalism for excited states that avoids many of the drawbacks associated with empirical or semi-empirical methods. We will illustrate applications of time-dependent DFT to a variety of systems ranging from molecules and atomic clusters to quantum dots, which contain several hundred atoms.