Dear Prof. Samir Ranjan Meher ,
The solution is already written in your email:
The DOS at the Fermi level is too small:
DOS(E_Fermi) = -0.1639E-79
This means that most likely the system has a gap,
and hence it should NOT be treated as a metal
Therefore, please remove this from your input file:
> occupations = 'smearing', smearing = 'mv', degauss=0.001
In any case, if you use linear response theory to compute U for Zn-3d you will
obtain a very large value. Check this paper: K. Yu and E.A. Carter, J. Chem.
Phys. 140, 121105 (2014)
HTH
Iurii
--
Dr. Iurii TIMROV
Senior Research Scientist
Theory and Simulation of Materials (THEOS)
Swiss Federal Institute of Technology Lausanne (EPFL)
CH-1015 Lausanne, Switzerland
+41 21 69 34 881
http://people.epfl.ch/265334
________________________________
From: users <[email protected]> on behalf of Samir
Ranjan Meher <[email protected]>
Sent: Wednesday, November 3, 2021 4:01:43 PM
To: [email protected]
Subject: [QE-users] Error with hp.x while calculating Hubbard U parameter
Hello everyone,
Greetings.
I am facing the following error while trying to obtain the "Hubbard-U"
parameter for Zn in ZnO through linear response theory using hp.x.
WARNING: The Fermi energy shift is too big!
This may happen in two cases:
1. The DOS at the Fermi level is too small:
DOS(E_Fermi) = -0.1639E-79
This means that most likely the system has a gap,
and hence it should NOT be treated as a metal
(otherwise numerical instabilities will appear).
2. Numerical instabilities due to too low cutoff
for hard pseudopotentials.
Stopping...
STOP 1
The scf input file is as follows:
=======================================================
&control
calculation = 'scf',
prefix='zno',
pseudo_dir = 'D:/Data/samir/qe/pseudo',
outdir='D:/Data/samir/qe/ZnO/hp/tmp'
/
&system
ibrav = 4, nat=4, ntyp= 2, a = 3.2494, c = 5.2038
ecutwfc = 60, ecutrho = 300
occupations = 'smearing', smearing = 'mv', degauss=0.001
lda_plus_U=.TRUE.
lda_plus_U_kind = 0,
U_projection_type = 'ortho-atomic'
Hubbard_U(1)=1.d-10
/
&ELECTRONS
mixing_mode='plain'
mixing_beta = 0.7,
conv_thr = 1.0d-10,
/
ATOMIC_SPECIES
Zn 65.39000 Zn.pbesol-dnl-kjpaw_psl.1.0.0.UPF
O 15.99940 O.pbesol-n-kjpaw_psl.1.0.0.UPF
ATO&control
calculation = 'scf',
prefix='zno',
pseudo_dir = 'D:/Data/samir/qe/pseudo',
outdir='D:/Data/samir/qe/ZnO/hp/tmp'
/
&system
ibrav = 4, nat=4, ntyp= 2, a = 3.2494, c = 5.2038
ecutwfc = 60, ecutrho = 300
occupations = 'smearing', smearing = 'mv', degauss=0.001
lda_plus_U=.TRUE.
lda_plus_U_kind = 0,
U_projection_type = 'ortho-atomic'
Hubbard_U(1)=1.d-10
/
&ELECTRONS
mixing_mode='plain'
mixing_beta = 0.7,
conv_thr = 1.0d-10,
/
ATOMIC_SPECIES
Zn 65.39000 Zn.pbesol-dnl-kjpaw_psl.1.0.0.UPF
O 15.99940 O.pbesol-n-kjpaw_psl.1.0.0.UPF
ATOMIC_POSITIONS {angstrom}
Zn -0.000016 1.876051 0.000000
Zn 1.624700 0.938040 2.601900
O -0.000016 1.876051 1.988372
O 1.624700 0.938040 4.590272
K_POINTS {automatic}
8 8 4 0 0 0
=================================================================
Can anybody suggest any solution to this?
Thank you,
Best wishes
Samir Ranjan Meher
Assistant Professor
Department of Physics
School of Advanced Sciences
Vellore Institute of Technology, Vellore
Tamilnadu- 632014
India
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