[Wien] Slab symmetry with SOC

[pluto at physics.ucdavis.edu]

Dear WIEN2k experts,

Unfortunately nobody has commented on my email below.

I believe that in my 15-atom Fe(001) slab, with magnetization along 100
and SOC included, there will be a mirror 100 plane (space group 6).
However, I have a feeling that there are more symmetries. For example I
have a feeling, that there should be an inversion symmetry, or at least
that the 100 axis should be a two-fold rotation axis. I am not able to
include these symmetries.

My calculations work well with fully primitive cell, and also with space
group 6 (actually sgroup rotates the slab, so that mirror plane becomes
001, but this of course does not matter). But I think that in every
problem one should include the necessary symmetries a priori, not only to
save time, but to avoid some spurious results.

Could you please give me at least some hint? I could also send my slab if
necessary.

Regards,
Lukasz





On 12/5/2013 10:03 AM, pluto at physics.ucdavis.edu wrote:

Dear WIEN2k experts,

I am calculating 29-atom Fe(001) slab with SOC with easy axis along [100].

Without SOC one can find more symmetries, and one has only 15 inequivalent
atoms. However, when performing the calculation with such slab the results
are different compared to the complex calculation with "pure" slab of 29
atoms. I believe that the correct result in this calculation is that
surface bands along [100] and [-100] are the same, and bands along [010]
and [0-10] are different. So one should have 3 slightly different set of
surface bands: along [100] (identical to [-100]), [010], and [0-10].

Of course on the opposite surfaces of the slab things will have the
inversion symmetry.

I believe that one of the programs, e.g. symmetso should in principle be
able to find out, whether the symmetries are correct or not, and produce
the correct struct file, which is possibly a bit more symmetric than the
original file.

Please advise.

Regards,
Lukasz