<div dir="ltr">Dear users and developers,<div>I posted the below question more than two weeks ago. However, I have not received any response. Any feedback or suggestion is greatly appreciated. Thanks in advance </div><div><br></div><div>Zeina <br><div class="gmail_quote">---------- Forwarded message ----------<br>From: <b class="gmail_sendername">Zeina Al-Dolami</b> <span dir="ltr"><<a href="mailto:zaldolam@email.uark.edu">zaldolam@email.uark.edu</a>></span><br>Date: Tue, Apr 28, 2015 at 3:54 PM<br>Subject: flat band structure<br>To: <a href="mailto:pw_forum@pwscf.org">pw_forum@pwscf.org</a><br><br><br><div dir="ltr">Dear <span style="color:rgb(0,0,0)">Pwscf's developers and users,</span><div><font color="#000000">I have started using quantum espresso recently for my research that focuses on investigating the mechanical and electrical properties of carbon based materials. I ran several examples of wannier90-1.2 to gain more understanding and insight of what I need to consider when running simulations for quantum conductance. However, I have realized that I need to reproduce the band structures of carbon based materials that have been already published then move to using wannier90. I came across this paper <a href="http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.3469647" target="_blank">http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.3469647</a> page242. It is basically a linear chain of 5 carbon atoms. Also, Accelrys Software, DMol programme, was used in this paper. I used the below scf and band files to reproduce the same band structure. However, the band structure that was produced contains flat bands only. I went through the pw-forum to find whether there was similar question or not. I found some discussions related to band structure and other suggestions that I have considered but no success, such as <a href="http://qe-forge.org/pipermail/pw_forum/2005-December/078012.html" target="_blank">http://qe-forge.org/pipermail/pw_forum/2005-December/078012.html</a></font><span style="color:rgb(0,0,0)"> . Would you please</span><font color="#000000"> tell me what I missed in my calculations? It is worth to mention that I have tried to use the same parameters available in this paper in my simulation. Any suggestion and feedback is greatly appreciated. Apologies if my question seems trivial because I am still at the beginning and have no background in this field. Looking forward to hearing from you. Thanks in advance </font></div><div><font color="#000000"><br></font></div><div><font color="#000000">Zeina </font></div><div><font color="#000000"><br></font></div><div><font color="#000000">scf file </font></div><div><font color="#000000"><br></font></div><div><font color="#000000">&CONTROL</font></div><div><font color="#000000"> calculation = 'scf',</font></div><div><font color="#000000"> restart_mode= 'from_scratch',</font></div><div><font color="#000000"> verbosity = 'high'</font></div><div><font color="#000000"> pseudo_dir = '/pseudo',</font></div><div><font color="#000000"> outdir = './',</font></div><div><font color="#000000"> prefix = '5cc',</font></div><div><font color="#000000"> tstress = .f.,</font></div><div><font color="#000000"> tprnfor = .t.,</font></div><div><font color="#000000">/</font></div><div><font color="#000000">&SYSTEM</font></div><div><font color="#000000"> ibrav = 1,</font></div><div><font color="#000000">! a = 6.520,</font></div><div style="color:rgb(0,0,0)">! b = 1.304,</div><div><span style="color:rgb(0,0,0)">! c = 1.304,</span></div><div><font color="#000000"> celldm(1) = 12.3210,</font></div><div><span style="color:rgb(0,0,0)"> cosbc = 0.,</span></div><div><font color="#000000"> cosac = 0.,</font></div><div><font color="#000000"> cosab = 0.,</font></div><div><font color="#000000"> nat = 5,</font></div><div><font color="#000000"> ntyp = 1,</font></div><div><font color="#000000"> ecutwfc = 30.,</font></div><div><font color="#000000"> ecutrho = 240.,</font></div><div><font color="#000000"> occupations = 'smearing',</font></div><div><font color="#000000"> smearing = 'cold',</font></div><div><font color="#000000"> degauss = 0.03,</font></div><div><font color="#000000"> nspin = 1,</font></div><div><font color="#000000">/</font></div><div><font color="#000000">&ELECTRONS</font></div><div><font color="#000000"> mixing_beta = 0.4</font></div><div><font color="#000000"> electron_maxstep = 1000,</font></div><div><font color="#000000"> conv_thr = 1.D-10,</font></div><div><font color="#000000">/</font></div><div><font color="#000000">ATOMIC_SPECIES</font></div><div><font color="#000000">C 12.0107 C.pbe-rrkjus.UPF</font></div><div><font color="#000000"><br></font></div><div><font color="#000000">ATOMIC_POSITIONS (angstrom)</font></div><div><font color="#000000">C 0.183 0.000000000 0.000000000</font></div><div><font color="#000000">C 1.489 0.000000000 0.000000000</font></div><div><font color="#000000">C 2.791 0.000000000 0.000000000</font></div><div><font color="#000000">C 4.093 0.000000000 0.000000000</font></div><div><font color="#000000">C 5.399 0.000000000 0.000000000</font></div><div><font color="#000000"><br></font></div><div><font color="#000000">K_POINTS {automatic}</font></div><div><font color="#000000">6 1 1 0 0 0 </font></div><div><font color="#000000"> </font></div><div><font color="#000000"><br></font></div><div><font color="#000000"><br></font></div><div><font color="#000000">band file </font></div><div><font color="#000000"><div>&CONTROL</div><div> calculation = 'bands',</div><div> restart_mode= 'from_scratch',</div><div> verbosity = 'high'</div><div> pseudo_dir = '/pseudo',</div><div> outdir = './',</div><div> prefix = '5cc',</div><div> tstress = .f.,</div><div> tprnfor = .t.,</div><div>/</div><div>&SYSTEM</div><div> ibrav = 1,</div><div>! a = 6.520,</div><div>! b = 1.304,</div><div>! c = 1.304,</div></font><font color="#000000"><div> celldm(1) = 12.3210,</div><div> cosbc = 0.,</div><div> cosac = 0.,</div><div> cosab = 0.,</div><div> nat = 5,</div><div> ntyp = 1,</div><div> ecutwfc = 30.,</div><div> ecutrho = 240.,</div><div> occupations = 'smearing',</div><div> smearing = 'cold',</div><div> degauss = 0.03,</div><div> nspin = 1,</div><div>/</div><div>&ELECTRONS</div><div> mixing_beta = 0.4</div><div> electron_maxstep = 1000,</div><div> conv_thr = 1.D-10,</div><div>! diag_full_acc = .true.</div><div><br></div><div>/</div><div>ATOMIC_SPECIES</div><div>C 12.0107 C.pbe-rrkjus.UPF</div><div><br></div><div>ATOMIC_POSITIONS (angstrom)</div><div>C 0.183 0.000000000 0.000000000</div><div>C 1.489 0.000000000 0.000000000</div><div>C 2.791 0.000000000 0.000000000</div><div>C 4.093 0.000000000 0.000000000</div><div>C 5.399 0.000000000 0.000000000</div><div><br></div><div>K_POINTS {crystal}</div><div>6</div><div>0.00000000 0.00000000 0.00000000 1.00000000</div><div>0.16666667 0.00000000 0.00000000 1.00000000</div><div>0.33333333 0.00000000 0.00000000 1.00000000</div><div>0.50000000 0.00000000 0.00000000 1.00000000</div><div>0.66666667 0.00000000 0.00000000 1.00000000</div><div>0.83333333 0.00000000 0.00000000 1.00000000</div><span class="HOEnZb"><font color="#888888"><div><br></div></font></span></font></div><span class="HOEnZb"><font color="#888888"><div><font color="#000000"> </font></div><div>-- <br><div><div dir="ltr"><span><font color="#888888">Zeina Al-Dolami<br>PhD Candidate<br>Microelectronics and Photonics Graduate Program <br>University of Arkansas<br>Fayetteville, AR 72701<br>Office: PHYS 244<br>Email: <a href="mailto:zaldolam@email.uark.edu" target="_blank">zaldolam@email.uark.edu</a><a href="mailto:cxm075@email.uark.edu" target="_blank"></a></font></span></div></div>
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</div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><span><font color="#888888">Zeina Al-Dolami<br>PhD Candidate<br>Microelectronics and Photonics Graduate Program <br>University of Arkansas<br>Fayetteville, AR 72701<br>Office: PHYS 244<br>Email: <a href="mailto:zaldolam@email.uark.edu" target="_blank">zaldolam@email.uark.edu</a><a href="mailto:cxm075@email.uark.edu" target="_blank"></a></font></span></div></div>
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