A Quantum Master Equation approach is applied to describe the exciton dynamics of the FMO complex, focusing on the effects of vibrations. Further, an excitonic model is applied to the description of the LH2 antenna complex to unravel the origin of the unusual B800 absorption band splitting and to connect this to observed exciton relaxation rates. In the second part a DFTB approach yielding a discrete representation of the electronic quantum mechanical charge density in terms of atom-centered Mulliken charges is used for the description of molecules nearby a metal nanosphere.<eng>
