<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">a CNT is represented, within QE, with the supercell approach, for example you choose a tetragonal cell, with z axis as a periodicity direction and x and y axes where vacuum space is added to<div class="">the lattice parameter(s) to prevent periodi replicas to interact with each other.</div><div class=""><br class=""></div><div class="">The positions of the C atoms for a nanotube of given diameter must be independently generated, I remember there are several scripts/tools available on line.</div><div class=""><br class=""></div><div class="">As an example, that should represent a (5,5) CNT (in this case an orthorhombic cell is considered):</div><div class=""> &CONTROL<br class=""> calculation='relax'<br class=""> title='C'<br class=""> restart_mode='from_scratch'<br class=""> nstep=100<br class=""> tprnfor=.true.<br class=""> outdir='./tmp'<br class=""> prefix='C'<br class=""> disk_io='default'<br class=""> pseudo_dir='/data/CODES/PWSCF/pseudo/'<br class=""> /<br class=""> &SYSTEM<br class=""> ibrav=6<br class=""> a=13<br class=""> b=13<br class=""> c=2.4941531628<br class=""> nat=20<br class=""> ntyp=1<br class=""> ecutwfc=30.0<br class=""> ecutrho=180.0<br class=""> /<br class=""> &ELECTRONS<br class=""> /<br class=""> &IONS<br class=""> /<br class="">ATOMIC_SPECIES<br class=""> C 12.011 C.pbe-van_bm.UPF<br class="">ATOMIC_POSITIONS { Angstrom }<br class="">C 3.4377467707 .0000000000 .0000000000<br class="">C 3.1405379467 1.3982575809 0<br class="">C 1.0623221745 3.2694914673 .0000000000<br class="">C -.3593423864 3.4189144339 0<br class="">C -2.7811955595 2.0206568529 .0000000000<br class="">C -3.3626237555 .7147477439 0<br class="">C -2.7811955599 -2.0206568526 .0000000000<br class="">C -1.7188733856 -2.9771760345 0<br class="">C 1.0623221739 -3.2694914676 .0000000000<br class="">C 2.3003015802 -2.5547437243 0<br class="">C 2.7811955595 2.0206568526 1.2470765814<br class="">C 1.7188733853 2.9771760349 1.2470765814<br class="">C -1.0623221742 3.2694914676 1.2470765814<br class="">C -2.3003015806 2.5547437240 1.2470765814<br class="">C -3.4377467707 0 1.2470765814<br class="">C -3.1405379470 -1.3982575806 1.2470765814<br class="">C -1.0623221745 -3.2694914673 1.2470765814<br class="">C .3593423861 -3.4189144339 1.2470765814<br class="">C 2.7811955592 -2.0206568533 1.2470765814<br class="">C 3.3626237552 -.7147477443 1.2470765814<br class="">K_POINTS { automatic }<br class="">1 1 2 1 1 1<br class=""><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On 27 Jan 2017, at 15:42, Uttam Paliwal <<a href="mailto:uttamphy@gmail.com" class="">uttamphy@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class=""><div class=""><br clear="all" class=""></div>hi <br class=""></div>is there any example to compute scf and nscf calculations of any kind of simple Carbon nanotube in QE. If there is any archive then please suggest how to construct a simple CNT in QE.<br class=""><div class=""><div class="">-- <br class=""><div class="gmail_signature" data-smartmail="gmail_signature"><font style="font-family:georgia,serif;color:rgb(51,51,255)" size="4" class="">Uttam Paliwal</font><br style="font-family:georgia,serif" class=""><b style="font-family:verdana,sans-serif" class=""><span style="" class="">Assistant Professor</span></b><b style="font-family:verdana,sans-serif" class=""><span style="" class=""></span></b><br style="font-family: verdana, sans-serif;" class=""><span style="font-family: verdana, sans-serif;" class="">Department of Physics</span><br style="font-family: verdana, sans-serif;" class=""><span style="font-family: verdana, sans-serif;" class=""></span><span style="font-family: verdana, sans-serif;" class="">J.N.V. University</span><br style="font-family: verdana, sans-serif;" class=""><span style="font-family: verdana, sans-serif;" class="">Jodhpur (India)<br class="">Phone- 7597908441<br class=""></span></div>
</div></div></div>
_______________________________________________<br class="">Pw_forum mailing list<br class=""><a href="mailto:Pw_forum@pwscf.org" class="">Pw_forum@pwscf.org</a><br class="">http://pwscf.org/mailman/listinfo/pw_forum</div></blockquote></div><br class=""><div class="">
-- <br class=""><br class="">Giovanni Cantele, PhD<br class="">CNR-SPIN<br class="">c/o Dipartimento di Fisica<br class="">Universita' di Napoli "Federico II"<br class="">Complesso Universitario M. S. Angelo - Ed. 6<br class="">Via Cintia, I-80126, Napoli, Italy<br class="">e-mail: <a href="mailto:giovanni.cantele@spin.cnr.it" class="">giovanni.cantele@spin.cnr.it</a><br class="">Phone: +39 081 676910<br class="">Skype contact: giocan74<br class=""><br class="">ResearcherID: <a href="http://www.researcherid.com/rid/A-1951-2009" class="">http://www.researcherid.com/rid/A-1951-2009</a><br class="">Web page: <a href="http://people.na.infn.it/~cantele" class="">http://people.na.infn.it/~cantele</a><br class="">
</div>
<br class=""></div></div></body></html>