SKM 2023 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 39: Phase Transformations: Simulation and Machine Learning

MM 39.6: Vortrag

Donnerstag, 30. März 2023, 13:00–13:15, SCH A 215

Structure-mapping workflow for the investigation of solid-solid phase transitions — •Artem Samtsevich, Christoph Scheurer, and Karsten Reuter — Fritz Haber Institute of the Max Planck Society, Berlin, Germany

Solid-solid transformations are common in nature and in the aging of functional materials. It is thus crucial to understand the origin of these complex phenomena at the atomistic level. The involved activated processes can be modeled as transitions between basins on a high-dimensional free energy landscape (FES). Using the harmonic approximation to transition state theory (hTST), one can estimate reaction rate constants from the location of saddle points on the FES. The chain-of-states method optimizes presumed pathways between two structural endpoints towards the minimum energy pathway (MEP), yielding transition state estimates. The generation of the initial pathway requires the mapping of atomic structures onto each other, which can be achieved either by purely geometrical methods (mapping of atomic positions and cells) or by the topology-based method, which maps the graphs of interatomic bonds. Both approaches are complementary to each other and generate a diverse set of mappings.

The combination of mapping algorithms with the chain-of-state method has recently been merged into a generalized workflow. We will present applications to phase transitions in high-energy-density and superhard materials [1,2] as well as catalyst aging.

[1] Wang, Y., Bykov, M., et al., Nat. Chem. 14, (2022).

[2] Kvashnin, A. G., Samtsevich A.I., Jetp Lett. 111, (2020).