Theoretical spectroscopy is a useful alternative to experiment: Not only is the assignment of spectroscopical signals to specific state-to-state transitions possible, but also environmental and temperature effects can be modelled in detail. We use quantum chemical ab initio methods or quantum dynamical techniques to evaluate spectra of isolated and embedded molecular species. Examples are (numbering refers to publication list):
- Time-independent and time-dependent (wavepacket) calculation of electronic and / or vibrational spectra of isolated molecular systems[19,28].
- Time-dependent open-system density matrix theory of electronic and / or vibrational spectra of large molecules or molecules embedded in an environment[18,39,50,51,84,95].
- Quantum chemistry of electronically excited states of biomolecules and dyes using CI, DFT-CI, and TD-DFT and R-MPn methods, possibly combined with molecular dynamics[57,58,64,75,82,84,91,95,97,136].
- Vibronically resolved electronic spectra using correlation functions[113,122,130,136,139].
- Time-dependent electronic spectroscopy by “dynamics on the fly”.
- Resonance Raman spectra using correlation functions.
- X-ray photoemission spectra.
Spectroscopy is often photophysics, i.e., no bonds are broken or made. The same is true for pure, laser-induced electron dynamics. In our group we are also interested in photochemistry, as stated above.