Development and validation of interatomic potentials and application to the simulation of phase transformations

I will present five short stories on the derivation of models of the interatomic interaction from Density Functional Theory (DFT), the validation of potentials and their application to the simulation of phase transformations. I will show how a systematic coarse graining of the electronic structure from DFT to the tight-binding approximation and analytic Bond-Order Potentials leads to magnetic potentials that capture the subtle interplay between magnetism and phase stability in iron. Further I will introduce the atomic cluster expansion as a formal many-atom expansion with an accuracy and transferability comparable to current machine learning approaches As different researchers typically have a different focus when developing potentials, interatomic potentials have various  application ranges. I will present automated high-throughput  calculations to validate a large number of interatomic potentials against DFT and to discern their application ranges I will then discuss the application of magnetic Bond-Order Potentials to simulating finite temperature magnetism in iron, in particular the ferromagnetic to paramagnetic phase transformation, the alpha-gamma transition and the prediction of mechanical properties. I will further summarize atomic simulations for phase stability, nucleation and solid-solid transformations with relevance to high-temperature materials.

About the speaker — Ralf Drautz received his Diploma in Physics (with distinction) from the Universität Stuttgart, Germany in 1998. He was a PhD student at the Max-Planck-Institut für Metallforschung, Stuttgart, Germany and received his PhD degree (Dr. rer. nat., summa cum laude) in 2003. Ralf Drautz was a research fellow (2003-2004), and a Senior Research Fellow and Materials Modelling Laboratory Research Fellow (2005-2008) at the University of Oxford. Since 2008, he has been Chair Professor at Ruhr-Universität Bochum in the Department of Physics and Astronomy, as well as the Director at the Interdisciplinary Centre for  Advanced Materials Simulation (ICAMS).