Unsupervised identification of crystal defects from atomistic potential descriptors

Autor(en)

Lukáš Kývala, Pablo Montero de Hijes, Christoph Dellago

Abstrakt

Identifying crystal defects is vital for unraveling the origins of many physical phenomena. Traditionally used order parameters are system-dependent and can be computationally expensive to calculate for long molecular dynamics simulations. Unsupervised algorithms offer an alternative independent of the studied system and can utilize precalculated atomistic potential descriptors from molecular dynamics simulations. We compare the performance of three such algorithms (PCA, UMAP, and PaCMAP) on silicon and water systems. Initially, we evaluate the algorithms for recognizing phases, including crystal polymorphs and the melt, followed by an extension of our analysis to identify interstitials, vacancies, and interfaces. While PCA is found unsuitable for effective classification, it has been shown to be a suitable initialization for UMAP and PaCMAP. Both UMAP and PaCMAP show promising results overall, with PaCMAP proving more robust in classification, except in cases of significant class imbalance, where UMAP performs better. Notably, both algorithms successfully identify nuclei in supercooled water, demonstrating their applicability to ice nucleation in water.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie, Fakultät für Geowissenschaften, Geographie und Astronomie

Journal

npj Computational Materials

Band

11

Anzahl der Seiten

8

ISSN

2096-5001

DOI

https://doi.org/10.48550/arXiv.2405.01320

Publikationsdatum

02-2025

Peer-reviewed

Ja

ÖFOS 2012

103043 Computational Physics, 103018 Materialphysik

ASJC Scopus Sachgebiete

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

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/4ea25d4c-f3e7-4431-9a20-aa87226371b8