[Pw_forum] GGA+U

[Giuseppe Mattioli]

Dear Sohail Ahmad
Before all why 5.0.1? It is not only an outdated version (10/05/2012!) which nobody has anymore interest in debugging/improving, but it is also the 
first version of the 5.x release, and it is therefore probably full of bugs that have been corrected later. If you want to stick to 5.x, then use at 
least the latest 5.4.0 version, or switch to 6.0.

>  Dear All QE usersI wish to study ScN using GGA+U.I am using QE-5.0.1,If I understood correctly , I need to modifyPW/set_hubbard_l.f90 and
> PW/tabd.f90

Yes, you should add data for Sc 

PW/src/tabd.f90

add

      CASE( 'Sc' )
        hubbard_occ = 1.d0

just before

      CASE( 'Ti', 'Zr', 'Hf' )
        hubbard_occ = 2.d0


/Espresso/5.4.0/Modules/set_hubbard_l.f90

     CASE( 'Ti', 'V',  'Cr', 'Mn', 'Fe', 'Co', 'Ni', 'Cu', 'Zn', &
           'Zr', 'Nb', 'Mo', 'Tc', 'Ru', 'Rh', 'Pd', 'Ag', 'Cd', &
           'Hf', 'Ta', 'W',  'Re', 'Os', 'Ir', 'Pt', 'Au', 'Hg'  )

add 'Sc' to the list -->

     CASE( 'Ti', 'V',  'Cr', 'Mn', 'Fe', 'Co', 'Ni', 'Cu', 'Zn', &
           'Zr', 'Nb', 'Mo', 'Tc', 'Ru', 'Rh', 'Pd', 'Ag', 'Cd', &
           'Hf', 'Ta', 'W',  'Re', 'Os', 'Ir', 'Pt', 'Au', 'Hg', &
           'Sc'  )

> exact value of U for ScN ?

Of course nobody knows! You should estimate it, there are several (semiempirical or self-consistent) ways. Read this to start:
Himmetoglu, B.; Floris, A.; de Gironcoli, S.; Cococcioni, M. Int. J. Quantum Chem. 2014, 114, 14-49

HTH
Giuseppe

On Saturday, February 25, 2017 07:08:19 PM Sohail Ahmad wrote:
>  Dear All QE usersI wish to study ScN using GGA+U.I am using QE-5.0.1,If I understood correctly , I need to modifyPW/set_hubbard_l.f90 and
> PW/tabd.f90 I found the file PW/src/tabd.f90 but don't see set_hubbard_l.f90 in PW/src 1.   Can any one explain where can I find this ?2.    What
> exact line/values need to be modified ?3.   exact value of U for ScN ? Any further guideline regarding input file is appreciated
> Best WishesSohail AhmadKing Khalid UniversitySaudi Arabia

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   Giuseppe Mattioli                            
   CNR - ISTITUTO DI STRUTTURA DELLA MATERIA   
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