[Wien] A way to evaluate if minimization without SO is correct ?

[Luc Fruchter]

It has been said many times that forces are not correct when spin-orbit 
is included.
Also, that the contribution of SO should generally be small, compared to 
energies that determine the equilibrium positions, so that minimization 
without SO should be a good approximation, for most cases.

I wonder, however, if the following scheme may help to get confidence 
that a minimization without SO indeed provides a structure close to 
equilibrium:

- perform minimization without SO,

- switch-on SO on heavy atoms of the equilibrated structure,

- fix these atoms, and relax the structure for the light atoms (like Oxygen)

- check if this relaxed structure is close to the one obtained at the 
first step.


Does this sound reasonable ?


Thanks