[Wien] NOMAD and Wien2k

[Pavel Ondračka]

Dear Wien2k mailing list,

I'm experimenting with the NOMAD database (nomad-lab.eu) and since I
remembered some old post from prof. Blaha on this topic, I just thought
I would ask here for user experience, because so far its not really
working that well for me.

So first of all the most annoying thing is that NOMAD detects two
"mainfiles" per directory, specifically the scf and scf0 files, but as
far as I can see it can't parse anything useful from the scf0 file (not
even the potential). The main downside is that it thinks there are two
calculations, while there is just one in fact and therefore creates lot
of useless entries.

Another think which I'm not sure how to approach is what to do when the
scf file is missing. I often do the main scf loop, than save_lapw to
another directory and after that I generate a new denser k-grid (for
DOS or optics) and just run lapw1, 2 and the tetra (or optic) or so on.
In this case I don't have scf file in the directory with the DOS or
optic calculations, but I would still like to upload this. The upload
somehow works, because the scf0 file from the old run stays there, so
at least NOMAD recognizes there are some Wien2k data, but it really
can't parse anything from the scf0 file (and in general I think that
using the scf0 file is a bug). I can make it somehow detect some
metadata by artificially creating a new fake scf file by combining the
old and new scfxxx files with cat... so that at least the NOMAD can
detect the composition, potential and some other basic things, but this
is clearly not optimal.

In general the NOMAD Wien2k parser cannot detect pretty much anything
beyond maybe structure information, and I will try to report all this
to the NOMAD developers to improve the parser, but I would be curious
if someone here had some better experience or can share some tricks,
how to make it work better for Wien2k with the current NOMAD state.

Best regards
Pavel