[Pw_forum] Projection of plane wave functions into atomic orbitals

[Francesco Antoniella]

Il lun, 2004-05-03 alle 17:26, Cyrille Barreteau ha scritto:
> 
> Dear pwscf users,
> 
> I have a question concerning the problem of projection of PW wave function
> on atomic orbitals.
> example 8 shows the case of bulk Ni with LDA pseudo pot NiUS.RRKJ3.UPF
> which uses two wave functions s and d (see below
In your pseudo the p channel is the local channel, i.e. you have no
projectors for the p because it has no nonlocal part at all for the p
pseudo.
This mean that the projecting proceudure cannot find the p-like charge.
It is better to use a directly separated pseudo as the vanderbilt pseudo
to overcome this problem.
Francesco
 
> 
>      2    6             Number of Wavefunctions, Number of Projectors
>   Wavefunctions         nl  l   occ
>                         4S  0  1.00
>                         3D  2  9.00
> 
> The result of the projection with projwfc.x gives the following decomposition:
> 
>   Atom #   1: total charge =   9.8849, s, p, d, f =   0.9347  0.0000  8.9501
>       Spilling Parameter:   0.0115
> 
> 
> 
> My question is the following: where have the p electrons gone?
> 
> It seems that eventhough the spilling parameter is not fantastic, it is
> not that bad and from the charge distribution it seems that the p electrons
> have in a way been projected on s orbitals! How is it possible?
> 
>   thanks for your help.
> 
>       cyrille
> 
> 
> 
> 
> 
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