for example, I want to get all Fermi energy of all Ca, Na and Li oxides with bandstructure, what properties should I query? It’s a ‘doc’, and I’ll get it from the efermi in the doc.
The key is “efermi”, see a list of tags you can query here.
Note that the fermi level is relative to the calculation itself and not absolutely defined. If you’re interested in this information, I would advise pulling down the full band structure and examining it yourself.