Hydrogen diffusion in magnesium using machine learning potentials: a comparative study

Autor(en)

Andrea Angeletti, Luca Leoni, Dario Massa, Luca Pasquini, Stefanos Papanikolaou, Cesare Franchini

Abstrakt

Understanding and accurately predicting hydrogen diffusion in materials is challenging due to the complex interactions between hydrogen defects and the crystal lattice. These interactions span large length and time scales, making them difficult to address with standard ab-initio techniques. This work addresses this challenge by employing accelerated machine learning (ML) molecular dynamics simulations through active learning. We conduct a comparative study of different ML-based interatomic potential schemes, including VASP, MACE, and CHGNet, utilizing various training strategies such as on-the-fly learning, pre-trained universal models, and fine-tuning. By considering different temperatures and concentration regimes, we obtain hydrogen diffusion coefficients and activation energy values which align remarkably well with experimental results, underlining the efficacy and accuracy of ML-assisted methodologies in the context of diffusive dynamics. Particularly, our procedure significantly reduces the computational effort associated with traditional transition state calculations or ad-hoc designed interatomic potentials. The results highlight the limitations of pre-trained universal solutions for defective materials and how they can be improved by fine-tuning. Specifically, fine-tuning the models on a database produced during on-the-fly training of VASP ML force-field allows the retrieval of DFT-level accuracy at a fraction of the computational cost.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

Università di Bologna, National Centre for Nuclear Research (NCBJ)

Journal

npj Computational Materials

Band

11

Anzahl der Seiten

8

ISSN

2096-5001

DOI

https://doi.org/10.48550/arXiv.2407.21088

Publikationsdatum

03-2025

Peer-reviewed

Ja

ÖFOS 2012

103018 Materialphysik, 103006 Chemische Physik, 103043 Computational Physics

ASJC Scopus Sachgebiete

Modelling and Simulation, Allgemeine Materialwissenschaften, Mechanics of Materials, Computer Science Applications

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/18ae2f4c-87dc-44bb-b141-0d8a0fe7483e