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>
Pw_forum mailing list<br>
<a href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br>
<a href="http://www.democritos.it/mailman/listinfo/pw_forum" target="_blank">http://www.democritos.it/mailman/listinfo/pw_forum</a><br>
<br></blockquote></div><br><br clear="all"><br>-- <br>###--------->   Arles V.   <---------###<br>