[Wien] Band Structure with p-characters

[Peter Blaha]

> I have a problem in plotting band structure with a character mapping. I
> have a tetragonal unit cell (space group 139) (LSCCO). In the CuO_2-plane
> there is Cu atom  in the corner  of the cell and O atoms  between Cu
> atoms.
>
> When plotting px and py characters of O atom  in a certain (Fermi level
> crossing) band there is strong px and weak py character in one direction
> of k-space from 0 0 0 to 0.5 0 0.
> In a k-direction normal  to that, say 0 0 0 to 0 0.5 0, the bands should
> be identical (they are) but now with strong py character and weak px.
>
> However,  when I calculate and plot the bands with wien2k the characters
> are identical in both directions. Could someone explain this to me? I'd
> make a guess that this has something to do with program automaticly
> rotating k-vectors into the irreducible
> wedge of the Brillouin zone, but is this true. And is there some obvious
> method to get characters to symmetry related directions.

Yes, WIEN "symmetrizes" the densities of all states, so that you do NOT
need to calculate the full BZ, but only the IBZ is enough.

You can calculate your px,py,pz charges separately when you put ISPLIT=8
into case.struct. But please do NOT use these results for "integral"
quantities (integrated over the BZ), since they would be wrong. However,
with this splitting you should find the desired px or py character into
the two directions respectively.

What should that be good for ?

                                      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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