Not all properties are computed for every material in the database. Common reasons:
- Band structure / DOS: Only available for materials with electronic structure calculations in Materials Project. AFLOW and JARVIS materials may not have these.
- Elastic properties: Require separate elastic constant calculations that have not been performed for all materials.
- Band gap = 0: Metals have zero band gap by definition; this is a real value, not missing data.
- Phase diagrams: Require all competing phases in the chemical system to be computed, which may not be complete for exotic element combinations.
Missing values are displayed as "—" or "N/A" in the interface. In the API, missing fields are either absent from the JSON response or set to null.