Get valence from pseudo potential

[superstar54]

In DFT+U calculation, user need to specify the manifold for the element, e.g.,

Co: 3d, O: 2p

Instead of inputting the value by the user manually, it would be better that we read the valence orbitals from the pseudo-potential and provide a dropdown for the user to select.

@unkcpz, you are the expert on pseudo. Do you know if this is already possible from Aiida? If not, can I assign this to you?

@AndresOrtegaGuerrero, any comments are welcome.

[AndresOrtegaGuerrero]

In #577 , I use pymatgen to get the valence per Kind, as a first approximation depending on the element i displayed the outer valence so the user can set the U value. However if we want to give more flexibility to the manifold is possible. Regarding the valence , this info can it be obtained in aiida-pseudo, like the z_valence (wondering no clue) ?

[AndresOrtegaGuerrero]

@superstar54 i guess we should "grep" the "Wavefunctions" from the pseudo file.

5 8 Number of Wavefunctions, Number of Projectors
Wavefunctions nl l occ
5S 0 2.00 Wavefunction
5P 1 6.00 Wavefunction
5D 2 3.90 Wavefunction
6S 0 2.00 Wavefunction
6P 1 0.00 Wavefunction

i notice this issue in aiida-pseudo aiidateam/aiida-pseudo#38 i left a comment there as well