Dresden 2020 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 7: Transport - Atoms and Ions II
MM 7.5: Talk
Monday, March 16, 2020, 12:45–13:00, IFW A
Autonomous Calculation Of Defect Transport Tensors — •Thomas Swinburne1 and Danny Perez2 — 1CNRS, CINaM, Marseille, France — 2T-1, Los Alamos National Laboratory, USA
Defect diffusion tensors are essential ingredients for mesoscale material models, but current calculation methods typically have unquantified uncertainty and require significant end user involvement. We combine a massively parallel sampling scheme controlled by Bayesian uncertainty quantification[1] with graph isomorphisms to compress the configuration space of isolated defects and automatically assign off-lattice defect displacement vectors to any found transition. We sample in a space irreducible under space group symmetries and derive an exact expression for the diffusion tensor involving only transitions between states irreducible under translation. A quantitative convergence metric is provided using bounds on the relative entropy.
[1] TD Swinburne and D Perez, Self-optimized construction of transition rate matrices from accelerated atomistic simulations with Bayesian uncertainty quantification. Phys. Rev. Materials 2018, 2, 053802