OPTIMADE Providers 2026: The Complete Database Directory
The OPTIMADE ecosystem looks different in 2026 than it did two years ago. Materials Project finished its r2SCAN migration. Alexandria added millions of new structures. Several smaller providers went offline; new ones came online. Most comparison resources date from 2022–2023. The r2SCAN migration alone changes which MP values you should trust. Follow an old tutorial and you may end up filtering on the wrong thermo endpoint. This directory covers every active OPTIMADE provider as of early 2026: entry counts, functionals, primary data types, compliance level, and the specific workflows each one handles well. ...