Differences in bandstructure in Quantum Espresso and Siesta for monolayer CrI3

Hello,

I am Shamik from India.

I calculated the band structure of monolayer CrI3 in Quantum Espresso. The exchange correctional functional I used is GGA-PBE and ultrasoft pseudopotential. I found that the bands (spin-up and spin-down) match with the bands available in the literature.

When I performed the band structure calculation of monolayer CrI3 in Siesta I found that the band structure does not match with the results of Quantum Espresso. The exchange correctional functional I used is GGA-PBE.

Why this big difference should exist?

It will be very helpful if someone can help me with this question.
Also guide me in the right direction.

 I am attaching the input files for your reference.

The input files of QUANTUM ESPRESSO for SCF and BANDS calculations are as below:

#####SCF==================================================
# Output variables

WriteMullikenPop 0
WriteBands .true.
SaveRho .false.
SaveDeltaRho .false.
SaveHS .false.
SaveElectrostaticPotential .false.
SaveTotalPotential .false.
WriteCoorXmol .false.
WriteMDXmol .false.
WriteMDhistory .false.
WriteEigenvalues .true.
COOP.Write .true.
WFS.Write.For.Bands .true.
WFS.band.min 1
WFS.band.max 108

=================================================

&control
    title = 'CrI3-scf'
    calculation='scf'
    prefix='cri3-recal',
    pseudo_dir = '/home/shamik/PP'
    outdir='/home/shamik/outdir'
    wfcdir='/home/shamik/outdir'
 /
 &system
    ibrav = 12
    celldm(1) = 13.105
    celldm(2) = 1.0
    celldm(3) = 5.45 !! 20AA
    celldm(4) = -0.500000
    nat = 8
    ntyp=2,
    ecutwfc = 50,
    ecutrho = 500,
    occupations = 'smearing',
    degauss = 0.005,
    smearing = 'methfessel-paxton',
    nspin = 2, !! Spin polarized calculation
    starting_magnetization(1)=0.2
    starting_magnetization(2)=0.2
 /

 &electrons
    conv_thr = 1.D-6

 /

ATOMIC_SPECIES
Cr 52 Cr.pbe-spn-rrkjus_psl.1.0.0.UPF
I 127 I.pbe-n-rrkjus_psl.1.0.0.UPF

ATOMIC_POSITIONS angstrom
Cr 3.417532951 1.939314693 3.665153995
Cr -0.050109469 -0.062994414 3.666024074
I 1.185996971 1.800677388 2.093677963
I 5.653246033 1.801286764 5.237586130
I 4.402237196 3.937951692 2.082815511
I 2.182167842 0.071536554 5.236445589
I 2.431503881 3.941023207 5.249062068
I 4.651470216 0.073932995 2.095990868

K_POINTS automatic
12 12 1 0 0 0

########################################

#####BANDS

&control
    title = 'CrI3-bands'
    calculation='bands'
    prefix='cri3-recal',
    pseudo_dir = '/home/shamik/PP'
    outdir='/home/shamik/outdir'
    wfcdir='/home/shamik/outdir'
 /
 &system
    ibrav = 12
    celldm(1) = 13.105
    celldm(2) = 1.0
    celldm(3) = 5.45 !! 20AA
    celldm(4) = -0.500000
    nat = 8
    ntyp=2,
    nbnd=42,
    ecutwfc = 50,
    ecutrho = 500,
    occupations = 'smearing',
    degauss = 0.005,
    smearing = 'methfessel-paxton',
    nspin = 2, !! Spin polarized calculation
    starting_magnetization(1)=0.2
    starting_magnetization(2)=0.2
 /

 &electrons
    conv_thr = 1.D-6

 /

ATOMIC_SPECIES
Cr 52 Cr.pbe-spn-rrkjus_psl.1.0.0.UPF
I 127 I.pbe-n-rrkjus_psl.1.0.0.UPF

ATOMIC_POSITIONS angstrom
Cr 3.417532951 1.939314693 3.665153995
Cr -0.050109469 -0.062994414 3.666024074
I 1.185996971 1.800677388 2.093677963
I 5.653246033 1.801286764 5.237586130
I 4.402237196 3.937951692 2.082815511
I 2.182167842 0.071536554 5.236445589
I 2.431503881 3.941023207 5.249062068
I 4.651470216 0.073932995 2.095990868

K_POINTS {crystal_b}
4
   0.0000000000 0.0000000000 0.0000000000 20
  -0.3333333333 0.6666666667 0.0000000000 20
   0.0000000000 0.5000000000 0.0000000000 20
   0.0000000000 0.0000000000 0.0000000000 20

#############################################

The input files of SIESTA for SCF and BANDS calculations are as below:

SystemName cri3-scf
SystemLabel cri3-scf

==================================================
# BASIS

PAO.BasisSize DZP
PAO.EnergyShift 0.01 Ry

==================================================
# K-points

%block kgrid_Monkhorst_Pack
36 0 0 0.0
0 36 0 0.0
0 0 1 0.0
%endblock kgrid_Monkhorst_Pack

==================================================
# Geometry
%include geo_dev_cri3.fdf

==================================================
# General variables

ElectronicTemperature 900 K
MeshCutoff 300 Ry
xc.functional GGA # Exchange-correlation functional
xc.authors PBE
SpinPolarized .true.
SolutionMethod diagon

BandLinesScale ReciprocalLatticeVectors

%block BandLines
1 0.0000 0.0000 0.000 \Gamma
80 -0.3333 0.6667 0.000 K
80 0.0000 0.5000 0.000 M
80 0.000 0.000 0.000 \Gamma
%endblock BandLines

==================================================
# SCF variables

MaxSCFIterations 1000 # Maximum number of SCF iter
DM.MixingWeight 0.005 # New DM amount for next SCF cycle
DM.Tolerance 0.0001 # Tolerance in maximum difference
DM.UseSaveDM .false. # to use continuation files
DM.NumberPulay 5
Diag.DivideAndConquer no
Diag.ParallelOverK yes
==================================================
# MD variables

MD.FinalTimeStep 1
MD.TypeOfRun CG
MD.NumCGsteps 000
MD.UseSaveXV .false.

==================================================
==================================================
# Output variables

WriteMullikenPop 0
WriteBands .true.
SaveRho .false.
SaveDeltaRho .false.
SaveHS .false.
SaveElectrostaticPotential .false.
SaveTotalPotential .false.
WriteCoorXmol .false.
WriteMDXmol .false.
WriteMDhistory .false.
WriteEigenvalues .true.
COOP.Write .true.
WFS.Write.For.Bands .true.
WFS.band.min 1
WFS.band.max 108

=================================================

Thank You
~Shamik