<html><body><div style="color:#000; background-color:#fff; font-family:bookman old style, new york, times, serif;font-size:14pt"><div>Dear QE Users</div><div><br></div><div>I am new with QE. I am following a default example for calculating/ploting band structure of simple graphene. The steps followed for relaxing, SCF NSCF calculations using PWgui was successful.<span style="font-weight: bold;"> I donot understand the command</span> (steps 4) on how to extract the band energy from graphene.band.out (after nscf calculation, step 3) to grapheneband.dat to be used for ploting the band sructure. following are the defaults steps followed:</div><div><br></div><div> 1.try to
relax the crystal structure and get equilibrium
configuration.<br>
</div><div><wbr> <wbr> <wbr> (using PWgui
to open input file"graphene.rx.in")<br>
<wbr> <wbr> <wbr> 2.try a scf
calculation for further band calculation.<br>
<wbr> <wbr> <wbr> (using PWgui
to open input file "graphene.scf.in")<br>
<wbr> <wbr> <wbr> 3.try to
calculate band energy for arbitary wavevectors.<br>
<wbr> <wbr> <wbr> (using PWgui
to open input file "graphene.band.in")<br>
<wbr> <wbr> <wbr> 4.use
bands.x in PP dictionary to extract band energy from
graphene.band.out
to <wbr> <wbr> <wbr> <wbr> <wbr></div>
<div>
<wbr> <wbr> <wbr> <wbr> <wbr>
grapheneband.dat.<br>
<wbr> <wbr> <wbr> <wbr> <wbr>
(mpiexec -n 2 ./bands.x < graphene.bands.in
> graphene.bands.out)</div>
<div>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr>Attention:
the number of CPU must be equal to <wbr>that of
pw.x</div>
<div>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr>If
.dat file is not found, inspect graphene.band.out file. There will
give</div>
<div>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
some <wbr>valuable <wbr>suggestion.<br>
<wbr> <wbr> <wbr> 5.use
grapheneband.dat to get picture.<br>
<wbr> <wbr> <wbr>
<wbr> (./plotband.x graphenebands.dat)<br>
<wbr> <wbr>
<wbr> <wbr> Then, there will some question
I must answer.<br>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
First:Emin, Emax > (the energy range appear in
picture)<br>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
Second:output file (xmgr) ><br>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
skipping ...<br>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
output file (ps) ><br>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
(choosing the type and giving a name of the picture)<br>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
Third:Efermi > <wbr> (giving the ferm
energy. This value can only obtaind after <wbr></div>
<div>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
I <wbr>check <wbr>the picture of energy
band)<br>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
Forth:deltaE, reference E (for tics)<br>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
(deltaE is the major tick of y axis.<br>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
reference E means the move the y axis. Traditional,
referenceE=Efermi)<br>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
Fifth:show the picture of energy band.<br>
<wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr>
ggv grapheneband</div><div><br></div><div>Thanks</div><div><br></div><div>Yusuf Zuntu</div><div>MSC candidate UPM malaysia<br></div><div><br></div><div><br></div><div><br></div></div></body></html>