Nick Papior

@pfebrer what do you think here?

> Hmm I'm not sure I understand the issues completely. I still don't understand the advantages of having `atoms` as a prefilter instead of just having an `OrbitalCategory` that can...

But the internal algorithm will the need to distinguish the two arguments... And will your method enable all variants of AtomsCategory... Hmm perhaps, I need to relook at the code!

Ok, I agree. It seems like a good idea, in this regard the opposite might also be interesting, an `AtomOrbitals` category ;)

You are correct. I'll see to it :)

So this is not so easily done. I need to add extra logic to enable sisl to write non-complete basis sets. The reason is that siesta only needs to store...

I agree. I would simply make a global identifier that writes which program wrote the file. That solves the issue. ;) I would like to focus on #221 before I...

Given this some thought and files should implement this `read_state` method

I'll reopen since it is not stable for real use. It is slow and only provides one way of dealing with it.

Good idea, could you have a look in the gf fortran sources, they can do this and is quite sufficient in performance!