[Wien] spin-orbit and forces

[Stefaan Cottenier]

Dear Wien-community,

In a calculation of a heavy impurity (Pb) in a heavy host lattice (hcp-Re),
I noticed the following behaviour which I don't understand:

First I relax the position of several neighbour shells around the impurity,
without spin-orbit coupling (it doesn't make sense to do this with
spin-orbit, as the forces by wien2k are incorrect for spin-orbit anyway).
Then I rerun the relaxed case with spin-orbit (adding spin-orbit has a
significant effect on e.g. the EFG of all the atoms). In this spin-orbit
calculation, the forces without the FOR switch are somewhat different from
the ones without spin-orbit, but with the FOR switch they are crazy :

grepline :FGL013 '*.scf' 3

no-SO.scf::FGL013:  13.ATOM                       221.045        190.184
0.081
no-SO.scf::FGL013:  13.ATOM                       221.067        190.208
0.195
no-SO.scf::FGL013:  13.ATOM                         1.120
 0.036         -0.079

with-SO.scf::FGL013:  13.ATOM                       214.047        185.388
0.151
with-SO.scf::FGL013:  13.ATOM                       214.040        185.393
0.095
with-SO.scf::FGL013:
OM                      -440.734      -3270.016       -582.134

(every time in the last iteration FOR is switched on)

I know one that the forces with spin-orbit are meaningless numbers in
wien2k, but I cannot remember to have met such high values before, and this
worries me a bit (indication of an error somewhere?). Can somebody confirm
that forces-with-SO can really go wild, or can somebody point me to the
likely error if this would not happen to be the case?

Basis set, k-mesh and Emax are well-converged, in1new is used.

Thanks,
Stefaan