Structural Chirality from Short-Range Order in Heteroanionic Materials
Abstract
Established routes to structural chirality in inorganic crystals predominantly depend on symmetry-lowering atomic displacements of an achiral parent structure. We show that chirality can instead be forced by the short-range order of two anion species over the sites of an achiral parent, independent of atomic displacements. ReO3-type oxyfluorides with a 2:1 anion stoichiometry, such as NbO2F, exhibit two ordering patterns, cis octahedral coordination and period-three anion-chain ordering, both of which are rooted in the off-centring of d0 cations. By direct enumeration, we prove that every arrangement combining both orderings on the smallest commensurate cell is chiral, belonging to a Sohncke space group. For NbO2F, density-functional theory (DFT) calculations predict a homochiral P3121 ground state. Wang-Landau Monte Carlo simulations of a DFT-trained cluster-expansion model predict that the chiral phase remains the equilibrium state up to a first-order transition at 494 K. We also identify three known vacancy-ordered compounds, BaZnO2, BaCoO2 and β-Fe2SeO, whose structures each map onto one of the enumerated chiral arrangements. Together, these results establish short-range order as a route to structural chirality, and mark heteroanionic and vacancy-ordered materials in which both orderings are active as candidates for new chiral phases.
Related
- Symmetry-Preserving Local Representation for Short-Range Interaction in Complex Materials
- Coupled dynamical Boltzmann transport equations with long-range electron-phonon and electron-electron interactions in two-dimensional materials
- Mechanical behavior of a gradient short range order high entropy alloy
- Crossover duality for the quantum long-range Ising chain: perturbation theory around the short-range endpoint and a DMRG test
- Short-Range Tests of the Gravitational Inverse-Square Law
BibTeX
@misc{morgan2026structural,
title = {{Structural Chirality from Short-Range Order in Heteroanionic Materials}},
author = {Benjamin J. Morgan},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2608.04841},
eprint = {2608.04841},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.04841},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Structural Chirality from Short-Range Order in Heteroanionic Materials
AU - Benjamin J. Morgan
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2608.04841
UR - https://arxiv.org/abs/2608.04841
AB - Established routes to structural chirality in inorganic crystals predominantly depend on symmetry-lowering atomic displacements of an achiral parent structure. We show that chirality can instead be forced by the short-range order of two anion species over the sites of an achiral parent, independent of atomic displacements. ReO_3-type oxyfluorides with a 2:1 anion stoichiometry, such as NbO_2F, exhibit two ordering patterns, cis octahedral coordination and period-three anion-chain ordering, both of which are rooted in the off-centring of d^0 cations. By direct enumeration, we prove that every arrangement combining both orderings on the smallest commensurate cell is chiral, belonging to a Sohncke space group. For NbO_2F, density-functional theory (DFT) calculations predict a homochiral P3_121 ground state. Wang-Landau Monte Carlo simulations of a DFT-trained cluster-expansion model predict that the chiral phase remains the equilibrium state up to a first-order transition at 494 K. We also identify three known vacancy-ordered compounds, BaZnO_2, BaCoO_2 and β-Fe_2SeO, whose structures each map onto one of the enumerated chiral arrangements. Together, these results establish short-range order as a route to structural chirality, and mark heteroanionic and vacancy-ordered materials in which both orderings are active as candidates for new chiral phases.
ER -