[QE-users] Problems with hp.x

[dv009200 at fh-muenster.de]

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