[QE-users] ?==?utf-8?q? Problems with hp.x

[Ing. Martin Matas]

Dear Dominik and everyone,
I just want to add the information that this problem of zinc chalcogenides was also recently reported by Flores, Moreira and Piotrowski in J. Phys. Chem. A 124 (2020) 3778–3785, doi.org/10.1021/acs.jpca.9b11415.

Martin Matas
Ph.D. student
University of West Bohemia


 Pondělí, 15 Červen, 2020 21:16 CEST, dv009200 at fh-muenster.de napsal:

> Hello everyone,
> 
> I'm trying to calculate the hubbard u parameter for Zn in Zinc sulfide
> (sphalerite structure) with the help of the hp.x code. The calculations
> terminate normally without any errors. The problem is that I get
> (presumably) way too high values for U that also won't converge (if I take
> the value I got from a one-shot calculation and plug it in the SCF input
> and then redo the HP calculation).
> 
> For example in the first step I calculate a U = 75.7035 in the second
> iteration I get U = 804.2405 and in the third U = 30999.2684.
> 
> This seems unreasonable considering that the calculations for the provided
> examples in the 'HP' folder work fine and converge fast without such a
> massive change to a certain value for U using the above described scheme.
> 
> Has someone an idea what is causing this trouble in my system? I already
> tried different PPs, functionals, U_projection_type, thresholds and k and
> q point grids all without success.
> 
> Below is my input for the scf and hp calculation
> 
> SCF-input:
>  &control
>     calculation='scf'
>     restart_mode='from_scratch',
>     pseudo_dir = '/home/dominik/codes/QE6.5/pseudo/'
>     outdir='/home/dominik/codes/QE6.5/tempdir/'
>     prefix='zns'
>  /
>  &SYSTEM
>     ibrav = 2
>     celldm(1)=10.291937439
>     nat   = 2
>     ntyp  = 2
>     ecutwfc = 60.0
>     ecutrho= 720.0
>     lda_plus_u = .true.
>     lda_plus_u_kind = 0
>     U_projection_type = 'atomic'
>     Hubbard_U(1) =  1d-8
>  /
>  &electrons
>     mixing_beta=0.7
>     conv_thr=1d-15
>  /
> ATOMIC_SPECIES
>  Zn  65.39  Zn.pbe-dn-rrkjus_psl.0.2.2.UPF
>  S   32.07  S.pbe-n-rrkjus_psl.0.1.UPF
> ATOMIC_POSITIONS {alat}
> Zn      0.000000   0.000000   0.000000
> S       0.250000   0.250000   0.250000
> K_POINTS automatic
> 12 12 12 0 0 0
> 
> 
> HP-input:
>  &inputhp
>    prefix='zns'
>    outdir='/home/dominik/codes/QE6.5/tempdir/'
>    nq1 = 2
>    nq2 = 2
>    nq3 = 2
>    conv_thr_chi = 1.0d-10
>    iverbosity =2
>  /
> 
> 
> Best regards
> 
> 
> Dominik Voigt
> 
> Dominik Voigt
> PhD Student University of Applied Sciences Münster
> Department of Physical Chemistry
> 
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