<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;"><br><br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><div id="yiv91243368"><table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font-family: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; font-size: inherit; line-height: inherit; font-size-adjust: inherit; font-stretch: inherit;" valign="top">Dear Eyvaz Isaaev<br> <br> I want to calculate electronic band structure of w-ZnO (1x1x2 super cell). But output band strcuture is overlaped. Whereas the band structure of w-ZnO unit cell is same as theoretical and experimental. I make this supercell using PHON code. Due to increase in cell along z-axis I increase its lattice parameter c 2 times in inputs (celldm=2*c/a). The inputs are attcahed below.<br><p style="margin-bottom: 0in;">
</p>
<p style="margin-bottom: 0in;"><br></p><p style="margin-bottom: 0in;"><br></p><p style="margin-bottom: 0in;"> &control
</p>
<p style="margin-bottom: 0in;"> Title = 'ZnO , hcp,a=3.2500,c=5.206
,c/a=1.6103125',
</p>
<p style="margin-bottom: 0in;"> calculation ='scf'
</p>
<p style="margin-bottom: 0in;"> restart_mode='from_scratch',
</p>
<p style="margin-bottom: 0in;"> pseudo_dir =
'/root/Pwscf/pseudo/',
</p>
<p style="margin-bottom: 0in;"> outdir
='/root/Pwscf/scratch/'
</p>
<p style="margin-bottom: 0in;"> prefix ='ZnO'
</p>
<p style="margin-bottom: 0in;"> tstress = .false.
</p>
<p style="margin-bottom: 0in;"> tprnfor = .false.
</p>
<p style="margin-bottom: 0in;"> /
</p>
<p style="margin-bottom: 0in;"> &system
</p>
<p style="margin-bottom: 0in;"> ibrav= 4,
</p>
<p style="margin-bottom: 0in;"> celldm(1) = 6.132075472,
</p>
<p style="margin-bottom: 0in;"> celldm(3) = 1.601846154,
</p>
<p style="margin-bottom: 0in;"> nat =4,
</p>
<p style="margin-bottom: 0in;"> ntyp =2,
</p>
<p style="margin-bottom: 0in;"> ecutwfc =25.0,
</p>
<p style="margin-bottom: 0in;"> ecutrho =300.0
</p>
<p style="margin-bottom: 0in;"> occupations ='smearing',
</p>
<p style="margin-bottom: 0in;"> smearing='methefessel_paxton',
</p>
<p style="margin-bottom: 0in;"> degauss = 0.02,
</p>
<p style="margin-bottom: 0in;"> /
</p>
<p style="margin-bottom: 0in;"> &electrons
</p>
<p style="margin-bottom: 0in;"> diagonalization='cg' ,
</p>
<p style="margin-bottom: 0in;"> conv_thr = 1.0e-8
</p>
<p style="margin-bottom: 0in;"> mixing_beta = 0.7
</p>
<p style="margin-bottom: 0in;"> /
</p>
<p style="margin-bottom: 0in;">ATOMIC_SPECIES
</p>
<p style="margin-bottom: 0in;"> Zn 65.409 Zn.pz-van_ak.UPF
</p>
<p style="margin-bottom: 0in;"> O 15.9994 O.pz-van_ak.UPF
</p>
<p style="margin-bottom: 0in;">ATOMIC_POSITIONS (crystal)
</p>
<p style="margin-bottom: 0in;"> Zn 0.333333333 0.666666667
0.0000000
</p>
<p style="margin-bottom: 0in;"> O 0.333333333 0.666666667
0.3817000
</p>
<p style="margin-bottom: 0in;"> Zn 0.666666667 0.333333333
0.5000000
</p>
<p style="margin-bottom: 0in;"> O 0.666666667 0.333333333
0.8817000
</p>
<p style="margin-bottom: 0in;">K_POINTS (automatic)
</p>
<p style="margin-bottom: 0in;">7 7 7 0 0 0</p>
<p style="margin-bottom: 0in;"><br>
</p>
<p style="margin-bottom: 0in;"><br>
</p>
<p style="margin-bottom: 0in;">This plot (after changing scf to nscf)
is same as experimental and theoretical
</p>
<p style="margin-bottom: 0in;"><br>
</p>
<p style="margin-bottom: 0in;"><br>
</p>
<p style="margin-bottom: 0in;">BUT</p>
<p style="margin-bottom: 0in;"><br>
</p>
<p style="margin-bottom: 0in;">when I make a cell of 8 atoms (1x1x2
supercell)</p>
<p style="margin-bottom: 0in;"> input is as below</p>
<p style="margin-bottom: 0in;"><br>
</p>
<p style="margin-bottom: 0in;"><br>
</p>
<p style="margin-bottom: 0in;"> &control
</p>
<p style="margin-bottom: 0in;"> calculation ='nscf' <= or bands<br>
</p>
<p style="margin-bottom: 0in;"> restart_mode='from_scratch',
</p>
<p style="margin-bottom: 0in;"> pseudo_dir =
'/root/Pwscf/pseudo/',
</p>
<p style="margin-bottom: 0in;"> outdir
='/root/Pwscf/scratch/'
</p>
<p style="margin-bottom: 0in;"> prefix ='ZnO'
</p>
<p style="margin-bottom: 0in;"> tstress = .false.
</p>
<p style="margin-bottom: 0in;"> tprnfor = .true.
</p>
<p style="margin-bottom: 0in;"> /
</p>
<p style="margin-bottom: 0in;"> &system
</p>
<p style="margin-bottom: 0in;"> ibrav = 4,
</p>
<p style="margin-bottom: 0in;"> celldm(1) = 6.132075472,
</p>
<p style="margin-bottom: 0in;"> celldm(3) = 3.203692308,
<span style="">
(due to increase in size along Z-direction C= 2*c )</span></p>
<p style="margin-bottom: 0in;"> nat = 8,
</p>
<p style="margin-bottom: 0in;"> ntyp = 2,
</p>
<p style="margin-bottom: 0in;"> ecutwfc = 25.0,
</p>
<p style="margin-bottom: 0in;"> ecutrho = 300.0
</p>
<p style="margin-bottom: 0in;"> occupations ='smearing',
</p>
<p style="margin-bottom: 0in;"> smearing ='methefessel_paxton',
</p>
<p style="margin-bottom: 0in;"> degauss =0.02</p><p style="margin-bottom: 0in;"> nbnd=20</p><p style="margin-bottom: 0in;"> nosym=.true.<br>
</p>
<p style="margin-bottom: 0in;"> /
</p>
<p style="margin-bottom: 0in;"> &electrons
</p>
<p style="margin-bottom: 0in;"> diagonalization='cg'
,mixing_mode='plain',
</p>
<p style="margin-bottom: 0in;"> conv_thr = 1.0e-8
</p>
<p style="margin-bottom: 0in;"> mixing_beta = 0.7
</p>
<p style="margin-bottom: 0in;"> /
</p>
<p style="margin-bottom: 0in;">ATOMIC_SPECIES
</p>
<p style="margin-bottom: 0in;"> Zn 65.38 Zn.pz-van_ak.UPF
</p>
<p style="margin-bottom: 0in;"> O 16.00 O.pz-van_ak.UPF
</p>
<p style="margin-bottom: 0in;">ATOMIC_POSITIONS (crystal)
</p>
<p style="margin-bottom: 0in;"> Zn 0.333333333 0.666666667
0.000000000
</p>
<p style="margin-bottom: 0in;"> Zn 0.333333333 0.666666667
0.500000000
</p>
<p style="margin-bottom: 0in;"> Zn 0.666666667 0.333333333
0.250000000
</p>
<p style="margin-bottom: 0in;"> Zn 0.666666667 0.333333333
0.750000000
</p>
<p style="margin-bottom: 0in;"> O 0.333333333 0.666666667
0.190850000
</p>
<p style="margin-bottom: 0in;"> O 0.333333333 0.666666667
0.690850000
</p>
<p style="margin-bottom: 0in;"> O 0.666666667 0.333333333
0.440850000
</p>
<p style="margin-bottom: 0in;"> O 0.666666667 0.333333333
0.940850000
</p>
<p style="margin-bottom: 0in;">K_POINTS <br></p><p style="margin-bottom: 0in;">32 <br> 0.0 0.0 0.5 1<br> 0.1 -0.1 0.1 2<br> 0.2 -0.2 0.2 3<br> 0.3 -0.3 0.3 4<br> 0.4 -0.4 0.4 5<br> 0.5 -0.5 0.5 6<br> 0.5 -0.5 0.4 7<br> 0.5 -0.5 0.3 8<br> 0.5 -0.5 0.2 9<br> 0.5 -0.5 0.1 10<br> 0.5 -0.5 0.0 11<br> 0.4 -0.4 0.0 12<br> 0.3 -0.3 0.0 13<br> 0.2 -0.2 0.0 14<br> 0.1 -0.1 0.0 15<br> 0.0 0.0 0.0 16<br> 0.0 0.0 0.1 17<br>
0.0 0.0 0.2 18<br> 0.0 0.0 0.3 19<br> 0.0 0.0 0.4 20<br> 0.0 0.0 0.5 21<br> 0.11 0.11 0.5 22<br> 0.22 0.22 0.5 23<br> 0.33 0.33 0.5 24<br> 0.33 0.33 0.4 25<br> 0.33 0.33 0.3 26<br> 0.33 0.33 0.2 27<br> 0.33 0.33 0.1 28<br> 0.33 0.33 0.0 29<br> 0.22 0.22 0.0 30<br> 0.11 0.11 0.0 31<br> 0.00 0.00 0.0 32<br>
</p>
<p style="margin-bottom: 0in;">
</p>
<p style="margin-bottom: 0in;"><br>
</p>
<p style="margin-bottom: 0in;">After changing scf to bands the
electronic structure is metallic (no band gap) and a I get different
electronic structure . Now please guide me how I can get true
electronic structure.</p>
<p style="margin-bottom: 0in;"><br>
</p>
<p style="margin-bottom: 0in;">Thanking in Advance</p><br><br>Muhammad Zafar<br>
PhD Scholar<br>
Department of Physics<br>
The Islamia University of Bahawalpur,Pakistan</td></tr></tbody></table></div></blockquote></td></tr></table>