Yes, many materials appear in multiple databases (MP, AFLOW, JARVIS) since they compute overlapping sets of structures. MatCraft does not deduplicate these entries because:
- Different methods: Each database uses different DFT settings (functionals, pseudopotentials, convergence criteria), so property values differ
- Useful for comparison: Seeing the same material from multiple sources lets you assess the sensitivity of computed properties to methodology
- Different properties: Some properties are only available from specific databases
When searching, you can filter by data source to see results from a single database. The material detail page shows the data source badge and links to the original database entry.