SKM 2023 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 29: Data Driven Materials Science: Big Data and Work Flows – Electronic Structure

MM 29.4: Talk

Wednesday, March 29, 2023, 12:30–12:45, SCH A 251

Charge-dependent Atomic Cluster Expansion — •Matteo Rinaldi, Anton Bochkarev, Yury Lysogorskiy, Matous Mrovec, and Ralf Drautz — Interdisciplinary Centre for Advanced Materials Simulation, Bochum, Germany

The atomic cluster expansion (ACE) [1,2,3] has proven to be a valuable tool to parametrize complex energy landscapes of pure elements and alloys outperforming popular approaches based on limited body-order descriptions. However, due to the local nature of the many body basis, it is inherently near-sighted. Therefore, long range interactions, such as electrostatics, are ignored in the description. Here, we introduce charge-dependent ACE to be able to tackle the missing electrostatic contributions. This formalism is based on the QEQ charge equilibration scheme from Rappe et al.^[4], where partial charges are obtained by equalizing atomic electronegativities and imposing charge conservation. Moreover, atomic electronegativities and hardness are considered as dependent on the local atomic environment. We demonstrate that our approach yields atomic charges in agreement with those obtained from popular partitioning schemes, such as Mulliken and Hirshfeld, including periodic and non-periodic systems, together with an accurate reproduction of the potential energy landscape. This work opens the possibility to model charge transfer and dielectric response within the increasingly popular ACE framework.

[1] R. Drautz, Phys. Rev. B 99, 014104 [2] Y. Lysogorskiy et al., npj Comput Mater 7, 97 (2021) [3] R. Drautz, Phys. Rev. B 102, 024104 [4] Rappe, J. Phys. Chem. 1991, 95, 8, 3358*3363