Скачать или смотреть Dan Widdowson's talk at MACSMIN 2025,

Speaker. Daniel Widdowson (Materials Innovation Factory, Liverpool, UK).

Title. Crystal Geomap: a visualisation & comparison tool for crystals.

Abstract. The number of experimentally measured crystal structures has risen exponentially in recent decades. Crystals are often classified by space group, which can be the same for distinct structures and different for similar ones; yet most continuous descriptors such as density can coincide for dissimilar crystals (a false positive). The Pointwise Distance Distribution (PDD) is a continuous descriptor (isometry invariant) akin to a crystal’s genetic code with no false positives amongst real organic crystals. PDDs contain enough information to reconstruct most crystals while comparisons take only milliseconds and are fast enough to find all matches in a database of a million structures in a few minutes, a task requiring years for comparison tools such as COMPACK. In 2021 we used invariants to find duplicates in the Cambridge Structural Database (CSD), 5 of which were investigated by curators. Since then the experiment’s speed and scope have grown considerably, culminating in a list of over 380,000 cross-references between the CSD and COD (Open Crystallography Database), comprising 80% of the COD. The PDD of a crystal is considered its coordinate in a universal ‘crystal space’, motivating us to create a visualisation and comparison tool based on our invariants. Our ‘Crystal Geomap’ app allows a user to compare or cluster crystals, to export or plot on chosen x and y axes where all crystals are seen in one space with physically meaningful coordinates.