Development, validation and application of a magnetic bond order potential for the Fe-C system
Final Report Abstract
The iron-carbon system belongs to the technologically most important binary systems since it is the basis of steel, one of the main materials in today’s society. A great deal of progress has been made in theoretical understanding of the physical, thermodynamic and mechanical properties of this system. However, explicit modelling of atomic-scale processes in modern steels with complex chemistries and microstructures still presents a significant challenge. The reason is that most of these processes are governed by a subtle interplay between chemical and magnetic interactions. The primary objective of this research project was to develop a state-of-the-art atomistic model that would be capable of describing quantitatively the atomic-scale behavior of the Fe- C system. Due to difficulties with tight-binding parametrizations, we decided to depart from the original plan and developed instead several models based on the atomic cluster expansion (ACE). ACE provides a complete basis in the space of atomic environments and can naturally incorporate a description of vectorial degrees of freedom in magnetic systems. Since the ACE basis is mathematically complete, ACE parameterizations can be improved and converged systematically. We developed general-purpose ACE for carbon, non-collinear magnetic ACE for iron, and first ACE models for binary systems composed of carbon and transition metals. All models were extensively validated and applied in various atomistic simulations. We demonstrated on several examples that ACE is not only superior in terms of accuracy but also computational efficiency and usually defines the Pareto front of current interatomic potentials.
Publications
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Efficient parametrization of the atomic cluster expansion. Physical Review Materials, 6(1).
Bochkarev, Anton; Lysogorskiy, Yury; Menon, Sarath; Qamar, Minaam; Mrovec, Matous & Drautz, Ralf
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Active learning strategies for atomic cluster expansion models. Physical Review Materials, 7(4).
Lysogorskiy, Yury; Bochkarev, Anton; Mrovec, Matous & Drautz, Ralf
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Atomic Cluster Expansion for Quantum-Accurate Large-Scale Simulations of Carbon. Journal of Chemical Theory and Computation, 19(15), 5151-5167.
Qamar, Minaam; Mrovec, Matous; Lysogorskiy, Yury; Bochkarev, Anton & Drautz, Ralf
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Atomistic simulations of pipe diffusion in bcc transition metals. Acta Materialia, 260, 119294.
Starikov, Sergei; Jamebozorgi, Vahid; Smirnova, Daria; Drautz, Ralf & Mrovec, Matous
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Disordering complexion transition of grain boundaries in bcc metals: Insights from atomistic simulations. Acta Materialia, 261, 119399.
Starikov, S.; Abbass, A.; Drautz, R. & Mrovec, M.
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Non-collinear Magnetic Atomic Cluster Expansion for Iron.
M. Rinaldi, M. Mrovec, Y. Lysogorskiy, A. Bochkarev, R. Drautz
