[Pw_forum] Not getting right Band structure
Neel Singh
neelphysics at yahoo.in
Tue Jul 28 11:54:14 CEST 2009
--- On Tue, 28/7/09, Neel Singh <neelphysics at yahoo.in> wrote:
Hi all,
I am new to PWSCF and trying to calculate Band structure of YVO4 but facing two problems ?
1.)No band is plotted in grpah above 0.0 value. The band structure is very large , as in the band Output file it is calculated like
End of band structure calculation
k = 0.0000 0.0000 0.0000 band energies (ev):
-12.5188 -12.0378 -11.9977 -11.5969 -11.2203 -11.0959 -10.5816 -10.5411
-10.4664 -10.4588 -10.0894 -10.0558 -9.6071 -9.5783 -9.0182 -8.9833
0.3058 0.6382 0.7747 0.9726 1.3117 1.4323 1.4740 1.5240
means band gap at gamma = 0.3058-(-8.9833)=
8.2891
which is very large ??
2) In the output of SCF and Bands , the output file has 4 warnings
warning: symmetry operation # 3 not allowed. fractional translation:
0.0000000 -0.5000000 0.1164604 in crystal coordinates
warning: symmetry operation # 4 not allowed. fractional translation:
0.0000000 0.0000000 0.1164604 in crystal coordinates
warning: symmetry operation # 25 not allowed. fractional translation:
0.0000000 0.0000000 0.1164604 in crystal coordinates
warning: symmetry operation # 26 not allowed. fractional translation:
0.0000000 -0.5000000 0.1164604 in
crystal coordinates
for this I have already increase the following quantities in the increments
kinetic-energy cutoff = 40.0000 Ry to 60
charge density cutoff = 250.0000 Ry to 400
But still the warnings are there.
Please help me. I will be very thankful. My Inputs for the calculations are following:
SCF INPUTS
&control
calculation='scf',
restart_mode='from_scratch',
prefix='yvo'
pseudo_dir = '/home/physics/pseudo/',
outdir='/home/physics/work/yvo/temp'
/
&system
ibrav =1, a=7.118300514, b= 7.118300514, c=6.289300454
, nat =24, ntyp= 3, ecutwfc = 40.0,ecutrho=250,
occupations='smearing',
smearing='mp', degauss=0.01,
/
&electrons
mixing_beta = 0.7
diagonalization = 'david'
conv_thr = 1.0e-4
/
&ions
/
ATOMIC_SPECIES
Y 88.90585 Y.pbe-nsp-van.UPF
V 50.9415 V.pbe-sp-van.UPF
O 15.9994 O.pbe-van_ak.UPF
ATOMIC_POSITIONS {angstrom}
Y 0.000000000 5.338725356 0.786162553
Y 3.559150238 1.779575118 3.930812762
Y 3.559150238
5.338725356 2.358487657
Y 0.000000000 1.779575118 5.503137866
V 0.000000000 1.779575118 2.358487657
V 3.559150238 5.338725356 5.503137866
V 0.000000000 5.338725356 3.930812762
V 3.559150238 1.779575118 0.786162553
O 0.000000000 3.090765987
1.262891534
O 3.559150238 6.649916224 4.407541744
O 3.559150238 4.027534488 4.407541744
O 0.000000000 0.468384251 1.262891534
O 5.807109607 5.338725356 2.835216639
O 4.870341106 1.779575118 5.979866849
O 3.559150238 3.090765987 1.881758675
O
0.000000000 6.649916224 5.026408885
O 0.000000000 4.027534488 5.026408885
O 3.559150238 0.468384251 1.881758675
O 4.870341106 5.338725356 0.30943357
O 5.807109607 1.779575118 3.45408378
O 1.311190868 1.779575118 3.45408378
O 2.247959369 5.338725356
0.30943357
O 2.247959369 1.779575118 5.979866849
O 1.311190868 5.338725356 2.835216639
K_POINTS {automatic}
2 2 2 0 0 0
------------------------------------------------------------------------------------------------
BANDS INPUT
---------------------------------------------------------------------------------------------------
&control
calculation='bands'
pseudo_dir = '/home/physics/pseudo/',
outdir='/home/physics/work/yvo/temp',
prefix='yvo',
/
&system
ibrav =1, a=7.118300514, b= 7.118300514, c=6.289300454, nat=24, ntyp=3,
ecutwfc = 40.0,ecutrho=250, occupations='smearing', smearing='mp', degauss=0.01, nbnd= 98,
/
&electrons
mixing_beta=0.7
conv_thr=1.0e-4
diagonalization = 'david'
/
&ions
/
ATOMIC_SPECIES
Y 88.90585 Y.pbe-nsp-van.UPF
V 50.9415 V.pbe-sp-van.UPF
O 15.9994 O.pbe-van_ak.UPF
ATOMIC_POSITIONS {angstrom}
Y 0.000000000 5.338725356
0.786162553
..
..
..
O ............
K_POINTS
26
0.000 0.000 0.000 1
0.000 0.000 0.125 1
0.000 0.000 0.250 1
0.000 0.000 0.375 1
0.000 0.000 0.500 1
0.125 0.125 0.500 1
0.250 0.250 0.500 1
0.375 0.375 0.500
1
0.500 0.500 0.500 1
0.500 0.500 0.333 1
0.500 0.500 0.166 1
0.500 0.500 0.000 1
0.375
0.375 0.000 1
0.250 0.250 0.000 1
0.125 0.125 0.000 1
0.000 0.000 0.000 1
0.000 0.000 0.166
1
0.000 0.000 0.333 1
0.000 0.166 0.500 1
0.000 0.333 0.500 1
0.000 0.500 0.500 1
0.000 0.500 0.333
1
0.000 0.500 0.166 1
0.000 0.500 0.000 1
0.000 0.333 0.000 1
0.000 0.166 0.000 1
---------------------------------------------------------------------------------------
-----------------------------------------------------------------------------
&inputpp
prefix = 'yvo'
outdir = '/home/physics/work/yvo/temp'
filband = 'yvobands.dat'
/
----------------------------------------------------------------------------------
-----------------------------------------------------------------------------------
yvobands.dat
-15 10
yvobands.xmgr
yvobands.ps
6.1088
1.0 6.1088
--------------------------------------------------------
-------------------------------------------------- please help . Thanks in Advance
With Regards.
Neel Singh
University of Delhi
India,
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