Dear Siesta users, I have a specific question concerning introducing ghost atoms. As we add them, we add new species whose Z values are negative. What about the labels of these species: should we better use new ones (that means we'll need pseudopot files with these new labels, and new entries in the PAO.basis block), or would it be safe to allow real and ghost atoms to share the same labels? I see that the corresponding calculation goes on without changing the labels, so that obviously every species is identified by its species number, so that the non-uniqueness of labels is not prohibited. I just wonder whether this might be potentially dangerous (like, something is identified by its label and not species number).
Thanks, Andrei Postnikov
