X-ray crystallography rarely captures chemical bonding between atoms of a structure in question. Most of the time distance-based heuristics are applied to establish the pairs of bonded atoms. One class of such heuristics depends on a set of bonding radii that estimate the idealised size of each chemical element in a bond. This publication describes an unsupervised workflow for deriving a bonding radii set from crystal structure data in the Crystallography Open Database.
@article{arxiv.2601.02017,
title = {Determination of bonding radii from small-molecule crystal structures},
author = {Eglė Šidlauskaitė and Andrius Merkys and Antanas Vaitkus and Algirdas Grybauskas and Saulius Gražulis},
journal= {arXiv preprint arXiv:2601.02017},
year = {2026}
}