[Wien] Non reproducibility of previous results: spin-orbit/orbital polarization

[ROBERTO LUIS IGLESIAS PASTRANA]

Dear all

While trying to reproduce some old tests for the bcc Fe system I bumped into a problem. Before I was using Wien2k_06.4 and now I'm using the latest Wien2k_08.3 release. I tried with exactly the same input files which, in a few cases, meant going back to slightly slower mixing schemes (BROYD instead of MSEC1 in case.inm) and with the new and improved ones as well. In a normal spin-polarized calculation there is no problem. However, when spin-orbit coupling and orbital polarization correction in case.inorb is added, I get different results. After executing initso_lapw, and running dstart, dstart up/dn again, the number of plane waves in case.outputd increases from 112 to 286. The case.inso file reads:

WFFIL
 4  1  0                      llmax,ipr,kpot
 -10.0000   7.00000           emin,emax (output energy window)
   0.  0.  1.                 direction of magnetization (lattice vectors)
 0                           number of atoms for which RLO is added
 0 0 0 0 0                    number of atoms for which SO is switch off; atoms

Subsequently,  I ran

runsp_lapw -so -cc 0.0001 ec 0.00001
save_lapw -d SOC

I build the right case.inorb

  2  1  0                     nmod, natorb, ipr
PRATT  1.0                    BROYD/PRATT, mixing
  1 1 2                          iatom nlorb, lorb
  1                              nmdep
  1                              Ncalc
  0. 0. 1.                    direction of M

and case.indmc

-10.                      Emin cutoff energy
 1                       number of atoms for which density matrix is calculated
 1  1  2      index of 1st atom, number of L's, L1
 0 0           r-index, (l,s)index

And
runsp_lapw -orb -so -cc 0.0001 -ec 0.00001

I'm not able to reproduce the original results, specially regarding the orbital moment, which is now:

:ORB001:  ORBITAL MOMENT:  0.00000  0.00000  0.06208 PROJECTION ON M  0.06209

and used to be:

:ORB001:  ORBITAL MOMENT:  0.00000  0.00000  0.07793 PROJECTION ON M  0.07793

Now, were there any significant changes in lapwdm or orb between these two Wien2k versions? I found some updates in the web page, of course, but I don't know if they would be significant as to change the orbital moment as much as a 20%.
One thing I noticed is that case.in0 has changed the last line from
  18  18  18    2.00    min IFFT-parameters, enhancement factor

to
  24  24  24    2.00    min IFFT-parameters, enhancement factor


Please excuse my ignorance, but I don't know if this is relevant or not. I'm using option 13 (PBE) for the XC potential.

Thanks in advance for any suggestions and merry X-mas to you all!

Roberto