Dear Muhammad Zafar:<br>In your structure, were optimized the lattice parameter and atomic positions..?? ecutwfc = 25.0 was obtained after a convergence..?? and finally, may be you need increase the k-points values (after a convergence).<br>
<br>Best<br><br><br>PhD stud. Arles V. Gil Rebaza<br>Institute of Physic of La Plata<br>La Plata - Argentine<br><br><br><div class="gmail_quote">2011/8/15 zafar rasheed <span dir="ltr"><<a href="mailto:zafartariq2003@yahoo.com">zafartariq2003@yahoo.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font:inherit" valign="top"><p style="margin-bottom:0in">
Dear All</p>
<p style="margin-bottom:0in"> I plot ZnO electronic
structure using this file given below</p>
<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 = 0.05,
</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"> 4 4 4 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 ='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 = .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>
(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"> /
</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 (automatic)
</p>
<p style="margin-bottom:0in"> 4 4 4 0 0 0</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><br>_______________________________________________<br>
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<br></blockquote></div><br><br clear="all"><br>-- <br>###---------> Arles V. <---------###<br>