Understanding structural and electronic properties of nano-scaled systems is an important prerequisite for their aimed development. Besides experimental methods quantum chemical calculations are crucial to obtain this knowledge. As an example, properties such as various types of spectra, bond energies etc. can be calculated, if the structure is known; on the other hand, by comparison of calculated and measured properties the geometric structure often can be obtained. Moreover, calculation of a series of nano-particles with different size and composition yields the data which are necessary for model building. Experimentally the systematic variation of these systems usually is not possible, and properties often can not be measured with sufficient accuracy. The further development of computer programs towards higher efficiency and accuracy as well as the extension of their functionality are necessary and continuously driven parallel to the applications. Current topics of research:

• Building principles of metal clusters with genetic algorithms in connection with density functional theory
• Investigation of binary clusters with perturbational approaches
• Hydrogen storage capacity of MOFs (metal organic frameworks)
• Support of groups with preparative focal point concerning quantum chemical problems and structure clarification
• Quantum chemical investigation of adsorption of organic molecules on metal surfaces with cluster and slab calculations
• Calculation of magnetic coupling parameters of bridged transition metal clusters basing on ab-initio data and simulation of magnetic susceptibility
• Magnetically induced ring currents in cyclic hydrocarbons
• Electronically excited states of light-harvesting complexes
• Further development of the program system TURBOMOLE (spin-orbit interactions, RI-methods, basis sets) and other programs for the provision of special tools for the above-mentioned problems