[Pw_forum] Projection of plane wave functions into atomic orbitals

[Cyrille Barreteau]

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)

     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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