The OPTIMADE specification defines a standard REST API for accessing materials databases, primarily focusing on crystal structures. Materials Cloud provides OPTIMADE REST APIs for its datasets through two providers: MAIN (mcloud) and ARCHIVE (mcloudarchive). Below, you'll find links to the index meta-database endpoints, as well as a list of all available databases.

Note: the OPTIMADE endpoints listed below are intended for people interested in programmatic access to the data. To browse the data interactively, please use the OPTIMADE client.