DFTB-based global optimization approach to large scale interfacial systems

• Applicant: Dr. Chiara Panosetti
• Subject Area: Theoretical Chemistry: Molecules, Materials, Surfaces ; Theoretical Chemistry: Electronic Structure, Dynamics, Simulation
• Term: from 2016 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 317276980

Aim of the project is the development of a versatile computational protocol geared towards the structure determination of large-scale interfacial systems. Such systems are generally of a level of complexity that dictates unbiased geometry determination with global optimization techniques. Simultaneously, intrinsically targeted are dimensions where quantum effects need to be captured and thus electronic structure methods are required for the energetics. Both constraints together lead presently to largely intractable computational costs. In this project I aim to overcome this bottleneck by introducing a geometric pre-screening at a more cost efficient level of theory and establishing a sampling approach specifically geared towards interfacial systems with often unknown composition and stoichiometry. For the latter I will rely on grand-canonical sampling techniques, while for the prior I will rely on Self-Consistent Charge Density Functional Tight Binding (SCC-DFTB). Specific efforts will be placed into a consistent parametrization scheme for SCC-DFTB that makes this approach available for all elements of the periodic systems. The developed protocol will be applied to diverse problems sharing the necessity for extensive structural screening, namely the prediction of Si and RuO2 surface reconstructions and the oxidation-induced redispersion of surface-supported TanOm clusters.

• DFG Programme: Research Grants