[QE-users] Adding a new element for LDA+U jobs

[Reinaldo Pis Diez]

Dear folks

According to the user guide, LDA+U works for a few elements, the 
list of them can be found in set_hubbard_l.f90 and set_hubbard_n.f90 
(both in Modules) and in tabd.f90 in PW/src. QE 6.5 is being used.

Looking at set_hubbard_l, I guess that hubbard_l is the l_max 
quantum number (l = 0 for H, l = 1 for C, N, O, etc). Looking at 
tabd, it is clear that hubbard_occ is the occupation of the above 
l_max.

I'm confused about the meaning of hubbard_n. I first guessed that it 
is related to the n quantum number because the following examples:

Element hubbard_n hubbard_l hubbard_occ
======= ========== ========= ===========
H                 1                0                 1.0
C,N,O          2                1            2.0,3.0,4.0
Ga, In        3,4               2                10.0

but the following is not clear to me:

Element hubbard_n hubbard_l hubbard_occ
======= ========== ========= ===========
As                3                1                 3.0

Arsenic has 3d^{10} 4s^{2} 4p^{3} electronic configuration. Could it 
be a mistake for Arsenic in set_hubbard_n.f90 or am I missing 
something about the nomenclature?

Thanks in advance, regards

Reinaldo

Center of Inorganic Chemistry
Natl Univ of La Plata
Argentina