Entwicklung und Implementierung neuer Berechnungsverfahren für elektronische Eigenschaften mit Dichtefunktionaltheorie-Rechnungen in kondensierter Materie
Final Report Abstract
This project was focused on pushing forward the frontiers of the predictive power of advanced computer simulations on modern supercomputers. In particular, this concerns the molecular and atomistic structure of ordered and disordered solids as well as liquids, which is based on relatively small changes in the electronic orbitals of these systems. During the three-year period of this project, a series of developments towards a more realistic density functional perturbation theory description of experimentally observable properties of supramolecular systems have been achieved. On the one hand, we worked on methods which combine quantum mechanical and non-quantum theories, which are mainly applicable to biological macromolecules. Here, the improvement of the theoretical description of the interface between quantum and non-quantum regions has been at the focus of the work. It could be shown that subtle changes in the interaction potential can substantially improve the accuracy of the predictions of such numerical simulations. On the other hand, we have explicitly incorporated thermal effects in the calculation of linear response properties of extended systems, where we could show in model systems that simple models based on qualtitative arguments can fail to describe the temperature dependence of spectropscopic observables correctly. We think that our simulations have illustrated the importance of the effects we have observed, and we expect that the numerical schemes we have used will become the standard approach for the prediction of complex spectra of supramolecular systems in the future. This project has led to a series of scientific publications in high-ranking journals, and several interesting follow-up questions are still being investigated and will lead to further articles on related topics.
Publications
- S. Komin, Ch. Gossens, I. Tavernelli, U. Röthlisberger and D. Sebastiani: NMR solvent shifts of adenine in aqueous solution from hybrid QM/MM Car-Parrinello molecular dynamics simulations J. Phys. Chem. B 111, 5225-5232 (2007)
- B. Kirchner and D. Sebastiani: Visualizing degrees of aromaticity for different barbaralane systems J. Phys. Chem. A 108, 11728 (2004)
- D. Sebastiani: Current densities and nucleus independent chemical shift (NICS) maps from reciprocal space density functional perturbation theory calculations ChemPhysChem 7, 164-175 (2006)
- J. Schmidt and D. Sebastiani: Anomalous temperature dependence of nuclear quadrupole interactions in strongly hydrogen bonded systems from first principles J. Chem. Phys. 123, 074501 (2005)
- J. Schmidt, A. Hoffmann, H.W. Spiess and D. Sebastiani: Bulk chemical shifts in hydrogen bonded systems from first principles calculations and solid-state-NMR J. Phys. Chem. B 110, 23204-23210 (2006)
