Save structure generator metadata

[niklassiemer]

Summary

Add structure generation metadata to our Atoms class in the structure factory.

Detailed Description

We have a lot of detailed information on how we set up our structures in the notebooks. However, looking at a particular structure in a job returns 'only' the bare positions/cell/types etc.

It would be great to store things like the creation routine (ase.bulk) or how often we simply repeated the structure in the metadata of the Atoms class.

Further Information, Files, and Links

[liamhuber]

I would love to see this. My naively preferred implementation would be Atoms(ASEAtoms, PyironObject) and to give PyironObject.storage a metadata field (and probably with the helper property metadata that exposes storage.metadata easier. Then I guess we would want some sort of decorator to wrap all the generators with like

def structure_metadata(structure_producing_method):
    def wrapper(*args, **kwargs):
        structure = structure_producing_method(*args, **kwargs)
        structure.metadata.source_code.method = structure_producing_method.__name__
        structure.metadata.source_code.args = args
        structure.metadata.source_code.kwargs = kwargs
        return structure
    return wrapper

(I'm just pulling that out of thin air, so no guarantee it works as written or has everything we want, but you get the idea).

[niklassiemer]

To have structure also on the same DataContainer footings sounds good to me :)

[pmrv]

I would just use the info dictionary that's already on every atoms, together with some small API to append and retrieve this data. That way we can also easily swap out the underlying storage, but we'd have the functionality straight way. Dual inheritance with PyironObject could be problematic due to the conflicting HDF impl's.