Dear 宋克楠,
your grid+supercell in incommensurate with the Dirac point, so its
position in energy is not constrained, using a grid which a multiple of
3 may fix the issue, however there could be another cause. Your cell has
a lot of vacuum space, with the PBE functional, you sometimes get a
wandering electron which ruins the band structure, reducing the vacuum
space to about 7Å maximum would fix it.
hth
On 02/09/2024 02:54, 宋克楠 wrote:
Dear All,
I am running a test calculation for the band structure of the pristine
monolayer graphene with 4×4×1
supercell through Quantum Espresso (QE).
This is my input file.
&CONTROL
title = 'SLG_441',
calculation = 'scf',
restart_mode = 'from_scratch',
pseudo_dir = './'
/
&SYSTEM
ibrav = 0,
nat = 32,
ntyp = 1,
ecutwfc = 50,
ecutrho = 200,
nbnd = 156,
occupations = 'smearing',
degauss = 1d-9,
smearing = 'gaussian'
/
&ELECTRONS
electron_maxstep = 100,
conv_thr = 1.0d-9,
mixing_mode = 'plain',
mixing_beta = 0.8d0,
diagonalization = 'david'
/
&IONS
ion_positions = 'from_input'
/
&CELL
cell_dynamics = 'none'
/
ATOMIC_SPECIES
C 12.0 C.pbe-n-kjpaw_psl.1.0.0.UPF
CELL_PARAMETERS (angstrom)
9.8400000000 0.0000000000 0.0000000000
-4.9200000000 8.5216901054 0.0000000000
0.0000000000 0.0000000000 23.4000000000
ATOMIC_POSITIONS (angstrom)
C 0.0000000000 0.0000000000 11.7000000000
C 1.2300000367 0.7101408633 11.7000000000
C -1.2300000000 2.1304225263 11.7000000000
C 0.0000000367 2.8405633896 11.7000000000
C -2.4600000000 4.2608450527 11.7000000000
C -1.2299999633 4.9709859160 11.7000000000
C -3.6900000000 6.3912675790 11.7000000000
C -2.4599999633 7.1014084423 11.7000000000
C 2.4600000000 0.0000000000 11.7000000000
C 3.6900000367 0.7101408633 11.7000000000
C 1.2300000000 2.1304225263 11.7000000000
C 2.4600000367 2.8405633896 11.7000000000
C 0.0000000000 4.2608450527 11.7000000000
C 1.2300000367 4.9709859160 11.7000000000
C -1.2300000000 6.3912675790 11.7000000000
C 0.0000000367 7.1014084423 11.7000000000
C 4.9200000000 0.0000000000 11.7000000000
C 6.1500000367 0.7101408633 11.7000000000
C 3.6900000000 2.1304225263 11.7000000000
C 4.9200000367 2.8405633896 11.7000000000
C 2.4600000000 4.2608450527 11.7000000000
C 3.6900000367 4.9709859160 11.7000000000
C 1.2300000000 6.3912675790 11.7000000000
C 2.4600000367 7.1014084423 11.7000000000
C 7.3800000000 0.0000000000 11.7000000000
C 8.6100000367 0.7101408633 11.7000000000
C 6.1500000000 2.1304225263 11.7000000000
C 7.3800000367 2.8405633896 11.7000000000
C 4.9200000000 4.2608450527 11.7000000000
C 6.1500000367 4.9709859160 11.7000000000
C 3.6900000000 6.3912675790 11.7000000000
C 4.9200000367 7.1014084423 11.7000000000
K_POINTS automatic
11 11 1 1 1 1
I am using C.pbe-n-kjpaw_psl.1.0.0.UPF pseudopotential with the
details below.
Origin: PS Library
Author: ADC
Generated using "atomic" code by A. Dal Corso v.6.3
Pseudopotential type: PAW
Functional type: PBE
Non Linear Core Correction
Scalar relativistic
I found that the Dirac point is located 0.027 eV above the Fermi
energy level, shown in the figure blow. Obviously, it is not correct.
Is the problem from the pseudopotential?
Would anyone please give me some suggestions on my input file and
recommend a proper pseudopotential to me?
Thank you in advance.
_______________________________________________
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country and on the free and peaceful scientific, cultural,
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_______________________________________________
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users mailing [email protected]
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--
Dr. Lorenzo Paulatto
IdR @ IMPMC - CNRS UMR 7590 & Sorbonne Université
phone: +33 (0)1 442 79822 / skype: paulatz
http://www.impmc.upmc.fr/~paulatto/ - https://anharmonic.github.io/
23-24/423 B115, 4 place Jussieu 75252 Paris CX 05
_______________________________________________
The Quantum ESPRESSO community stands by the Ukrainian
people and expresses its concerns about the devastating
effects that the Russian military offensive has on their
country and on the free and peaceful scientific, cultural,
and economic cooperation amongst peoples
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
