[Pw_forum] AIM routines for PWSCF ?

[Stefano de Gironcoli]

Goranka Bilalbegovic wrote:

>How important is the sentence in the header of voronoy.f90:
>"Note that this is a very rough way to associate charges to atoms
>  and that it is well defined only if all atoms are of the same type" ?
>  
>
I think it may be very important.

If I remember corectly if you calculate  the amount of charge contained 
in the Voronoy polyhedra
in an polar semiconductor in the zincblend structure the result is not 
what you expect:
the amount of charge around the cation is LARGER than the one around the 
anion, basically because
anion charge is more extended and spills out of the anion polyhedron 
into the cation one.
The physically sensible result is obtained by the Bader construction, 
that is however far more complicated
and is not presently implemented in PWscf.
 I think Mulliken or Lowdin charge analysis gives reasonable results.

Stefano de Gironcoli

>In addition, projwave calculates the Lowdin charges. 
>Perhaps, it is also useful ?
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