Continuous invariant-based asymmetries of periodic crystals quantify deviations from higher symmetry

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Majumder, Surya, Widdowson, Daniel, Elkin, Yury, Anosova, Olga, Cooper, Andrew I, Day, Graeme M, Kurlin, Vitaliy
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866918324169867264
author Majumder, Surya
Widdowson, Daniel
Elkin, Yury
Anosova, Olga
Cooper, Andrew I
Day, Graeme M
Kurlin, Vitaliy
author_facet Majumder, Surya
Widdowson, Daniel
Elkin, Yury
Anosova, Olga
Cooper, Andrew I
Day, Graeme M
Kurlin, Vitaliy
contents Ideal symmetry is known to break down under almost any noise. One measure of asymmetry in a periodic crystal is the relative multiplicity Z' of geometrically non-equivalent units. However, Z' discontinuously changes under almost any displacement of atoms, which can arbitrarily scale up a primitive cell. This discontinuity was recently resolved by a hierarchy of invariant descriptors that continuously change under all small perturbations. We introduce a Continuous Invariant-based Asymmetry (CIA) to quantify (in physically meaningful Angstroms) the deviation of a periodic crystal from a higher symmetry form. Our experiments on several Crystal Structure Prediction datasets show that about a half of simulated crystals have high values of CIA, while all experimental structures in these datasets have CIA=0. On another hand, many crystals with high values Z' in the Cambridge Structural Database (CSD) turned out to be close to more symmetric forms with Z'<=1 due to low values of CIAs.
format Preprint
id arxiv_https___arxiv_org_abs_2510_13746
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Continuous invariant-based asymmetries of periodic crystals quantify deviations from higher symmetry
Majumder, Surya
Widdowson, Daniel
Elkin, Yury
Anosova, Olga
Cooper, Andrew I
Day, Graeme M
Kurlin, Vitaliy
Metric Geometry
Materials Science
68U05, 74E15, 51M15
Ideal symmetry is known to break down under almost any noise. One measure of asymmetry in a periodic crystal is the relative multiplicity Z' of geometrically non-equivalent units. However, Z' discontinuously changes under almost any displacement of atoms, which can arbitrarily scale up a primitive cell. This discontinuity was recently resolved by a hierarchy of invariant descriptors that continuously change under all small perturbations. We introduce a Continuous Invariant-based Asymmetry (CIA) to quantify (in physically meaningful Angstroms) the deviation of a periodic crystal from a higher symmetry form. Our experiments on several Crystal Structure Prediction datasets show that about a half of simulated crystals have high values of CIA, while all experimental structures in these datasets have CIA=0. On another hand, many crystals with high values Z' in the Cambridge Structural Database (CSD) turned out to be close to more symmetric forms with Z'<=1 due to low values of CIAs.
title Continuous invariant-based asymmetries of periodic crystals quantify deviations from higher symmetry
topic Metric Geometry
Materials Science
68U05, 74E15, 51M15
url https://arxiv.org/abs/2510.13746