[Wien] case.in1 file and Local Orbitals

[Peter Blaha]

> Having a glance to the case.in1 files I've realized that there is apparently
> no regular choice made by lstart in the linearization energy of local orbitals
> (LO).
> Running the TiO2 case in the examples I've found (file TIO2_in1):
> 
> WFFIL        (WFPRI, SUPWF)
>   7.00       10    4 (R-MT*K-MAX; MAX L IN WF, V-NMT
>   0.30    5  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global APW/LAPW)
>  0    0.30      0.000 CONT 1
>  0   -4.35      0.005 STOP 1
>  1   -2.58      0.010 CONT 1
>  1    0.30      0.000 CONT 1
>  2    0.30      0.010 CONT 1
>   0.30    3  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global APW/LAPW)
>  0   -1.55      0.010 CONT 1
>  0    0.30      0.000 CONT 1
>  1    0.30      0.000 CONT 1

No, don't change anything.

Although intuitive, it is NOT true that a "local orbital" corresponds 
necessarily to a state with a fairly "localized (contracted) wavefunction".

LOs are just an additional basis set which allow the treatment of 2
principal qu.numbers (3s and 4s) at the same time. (The name LO comes
from its construction!, this basis function is constructed to be local, i.e.
is zero outside the sphere)

One gets (nearly) identical results when one sets the 3p as LO and
the 4p as "APW", or the other way around.

WIEN has some energy criterium and selects the "more important" state
as APW, and the "less important one as LO. In the TiO2 example

the O-2s and Ti 3p are considered "more important" than their 3s/4p partners,
while Ti 4s is more important than Ti 3s (which is almost a core state).

 




                                      P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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