[Pw_forum] Anatase primitive cell:Reg

[Suresh A]

Dear All,
I tried to get band strucuture for anatase primitive cell, but
the band structure was wrong when compared to previous work. I got the
following file using cif2cell program.
&CONTROL
title = 'TiO2' ,
calculation = 'scf',
outdir ='/home/suresh/Desktop/prim/tmp/',
prefix = 'anatase',
pseudo_dir = '/home/suresh/Desktop/prim/',
tstress = .true. ,
tprnfor = .true. ,

/

&SYSTEM
ibrav = 0,
A = 3.78450
nat = 6 ,
ntyp = 2 ,
ecutwfc = 80 ,
ecutrho = 500



/

&ELECTRONS



/
CELL_PARAMETERS {alat}
1.000000000000000 0.000000000000000 0.000000000000000
0.000000000000000 1.000000000000000 0.000000000000000
0.500000000000000 0.500000000000000 1.257008851895891
ATOMIC_SPECIES
Ti 47.86700 Ti.pz-mt_fhi.UPF
O 15.99940 O.pz-mt_fhi.UPF
ATOMIC_POSITIONS {crystal}
Ti 0.000000000000000 0.000000000000000 0.000000000000000
Ti 0.750000000000000 0.250000000000000 0.500000000000000
O 0.792000000000000 0.792000000000000 0.416000000000000
O 0.542000000000000 0.042000000000000 0.916000000000000
O 0.958000000000000 0.458000000000000 0.084000000000000
O 0.208000000000000 0.208000000000000 0.584000000000000
K_POINTS automatic
4 4 2 0 0 0
is this file is correct? And can someone post here anatase primitive cell
input file with ibrav=7.

Thanks in advance
With Regards,
A.Suresh,
Research Scholar,
Madurai Kamaraj University,
Madurai.

[Mike Atambo]

Suresh, your cell definition seems off to me, (8 atoms, i use 12 atoms
for anatase, ) where did you get the cif file? and would you mind posting
that?
here is something posted in the forum in the past by Paolo:
http://qe-forge.org/pipermail/pw_forum/2015-November/108374.html

&control
calculation = 'relax'
restart_mode='from_scratch',
pseudo_dir = './',
outdir='./tmp/',
/
&system
ibrav= 6, celldm(1) = 7.19856, celldm(3) = 2.54638,
nat= 12, ntyp= 2,
ecutwfc =25.0,
ecutrho =150.,
occupations='smearing',degauss=0.01 ,
nspin=1,
/
&electrons
mixing_mode = 'plain'
mixing_beta = 0.4
conv_thr = 1.0d-9
/
&ions
/
ATOMIC_SPECIES
Ti 47.900 Ti12_pbe.van.UPF
O 15.999 O_pbe.van.UPF
ATOMIC_POSITIONS {crystal}
Ti 0.0000 0.0000 0.0000
Ti 0.0000 0.5000 0.2500
Ti 0.5000 0.5000 0.5000
Ti 0.5000 1.0000 0.7500
O 0.0000 0.0000 0.2066
O 0.0000 0.0000 -0.2066
O 0.0000 0.5000 0.4566
O 0.0000 0.5000 0.0434
O 0.5000 0.5000 0.7066
O 0.5000 0.5000 0.2934
O 0.5000 1.0000 0.9566
O 0.5000 1.0000 0.5434
K_POINTS {automatic}
4, 4, 2, 1, 1, 1

its an input with ibrav 6 though, not 7.

The original thread is here if you care to follow:
http://qe-forge.org/pipermail/pw_forum/2015-November/108374.html

Post by Suresh A
Dear All,
I tried to get band strucuture for anatase primitive cell, but
the band structure was wrong when compared to previous work. I got the
following file using cif2cell program.
&CONTROL
title = 'TiO2' ,
calculation = 'scf',
outdir ='/home/suresh/Desktop/prim/tmp/',
prefix = 'anatase',
pseudo_dir = '/home/suresh/Desktop/prim/',
tstress = .true. ,
tprnfor = .true. ,
/
&SYSTEM
ibrav = 0,
A = 3.78450
nat = 6 ,
ntyp = 2 ,
ecutwfc = 80 ,
ecutrho = 500
/
&ELECTRONS
/
CELL_PARAMETERS {alat}
1.000000000000000 0.000000000000000 0.000000000000000
0.000000000000000 1.000000000000000 0.000000000000000
0.500000000000000 0.500000000000000 1.257008851895891
ATOMIC_SPECIES
Ti 47.86700 Ti.pz-mt_fhi.UPF
O 15.99940 O.pz-mt_fhi.UPF
ATOMIC_POSITIONS {crystal}
Ti 0.000000000000000 0.000000000000000 0.000000000000000
Ti 0.750000000000000 0.250000000000000 0.500000000000000
O 0.792000000000000 0.792000000000000 0.416000000000000
O 0.542000000000000 0.042000000000000 0.916000000000000
O 0.958000000000000 0.458000000000000 0.084000000000000
O 0.208000000000000 0.208000000000000 0.584000000000000
K_POINTS automatic
4 4 2 0 0 0
is this file is correct? And can someone post here anatase primitive cell
input file with ibrav=7.
Thanks in advance
With Regards,
A.Suresh,
Research Scholar,
Madurai Kamaraj University,
Madurai.
_______________________________________________
Pw_forum mailing list
http://pwscf.org/mailman/listinfo/pw_forum

[Suresh A]

Dear Mike,
I am sorry for this late reply. Anatase structure has body
centered tetagonal space group. If one use ibrav=7 (primitive cell) then
there will be only six atoms in the unit cell. If ibrav=6 (conventional
cell)then one have to include 12 atoms in the atomic positon of input file.
Dr. Paolo pointedout for input file of simple tetragonal (conventional
cell) anatase structure.
I used cif2cell programme for my input file.
With Regards,
A.Suresh,
Research Scholar,
Madurai Kamaraj University,
Madurai.