XAS databases and repositories – perspective and current status

X-ray absorption fine structure (XAFS) methods are widely used, and there is a strong demand to establish well-maintained and reliable XAFS databases. Several XAFS databases have been independently developed based on different requirements of the XAS users’ community. These databases mainly consist of XAS data of references or standard samples from dedicated beamlines at synchrotron facilities available to the individuals or group involved in their development. In the present paper, we report the recent activities regarding the development of XAS databases as presented and discussed during Q2XAFS 2023 workshop held at the Australian Synchrotron in Melbourne (Australia). The features of already existing XAS databases are briefly discussed and summarized. The important components and features of two recently developed XAS databases – MDR XAFS database from Japan and RefXAS database under DAPHNE4NFDI from Germany are described. We report on the recent activities and status of these databases. We further discuss the general challenges of developing such databases, including sustainability, metadata structure, sample identification, curation, user feedback and standardization of data formats.