[Wien] [Wien2k Users] QTL Warning for Fe_cubic_Space Group 225

[Kurt Lejaeghere]

> When actually do we have to incorporate LO's in case.in1?
> 1. When the *******WARNING****** message comes? You mention that "The reason
> for changing the values is that I wanted to tune the linearization energies
> as much as possible to the 'real' energies, in order to be sure to lose the
> warning".

When you add an additional LO function, you increase the basis set.  
This is a good way to improve the flexibility when the linearization  
becomes as good as it gets.

> 2. To make the value of ENE more accurate?

Since you increase the dimension of the basis set, yes, of course.

> 3. Does such incorporation of LO's really matter when we consider
> lanthanides?
> 4. As suggested by Stefaan (Guide) we have to run using in1new switch, then
> we automatically get the linearization energies. Is the same thing true for
> lanthanides 5. In cases of lanthanides, there is one LO for L=3 and one for
> L=2 in the default case.in1. Can we, in similar way add one more LO for L=2
> in such a case.

I don't see why the same reasoning shouldn't apply to lanthanides.

> 6. You also mention that QTL warning can be actually ignored, but I have
> found that it does give an error in the DOS calculations unless our case.scf
> file is free of any such warnings.
> The issue is when to make such changes?

I have no experience with DOS calculations, but if you really need to  
clear those warnings, the extra LO function should do the trick. If  
you however just want to fit an equation of state, the energies with  
warning are good enough to determine the minimal energy and similar  
things.

I highly recommend Stefaan's guide and the WIEN2k user guide  
(especially the FAQ) for some of your questions, since some of them  
are explained in more detail there, including the addition of a LO  
function in order to avoid ghost bands.

Kind regards

Kurt