Hi, Zhu Xi<br><br>to my knowledge , we always compare workfunctions of nanotubes with experimental<br>data, but not fermi level !<br>In order to check your result, you can follow nicolas's suggestion : using pp.x to obtain the vacuum level, the difference between fermi level and vacuum level is workfunction of nanotube.
<br>please note, due to periodic images' interaction, the cell size of your system will affect the final result you obtain. <br><br>Bests,<br>Hai-Ping<br><br><br><div class="gmail_quote">On Jan 10, 2008 6:37 AM, Zhu Xi <
<a href="mailto:ustc0200@gmail.com">ustc0200@gmail.com</a>> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div>Hi Nicholas,</div>
<div>thanks for your reply, but to my understaning, the 0.625eV fermi energy is wrong, it should be between -5~-4eV, I don't know why the code give such a fermi energy.....<br><br> </div><div><div></div><div class="Wj3C7c">
<div><span class="gmail_quote">On 1/10/08, <b class="gmail_sendername">Nicholas E. Singh-Miller</b> <<a href="mailto:nedward@mit.edu" target="_blank">nedward@mit.edu</a>> wrote:</span>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0px 0px 0px 0.8ex; padding-left: 1ex;">Dear Zhu Xi,<br><br>I have not run your input file, but assuming that it is correct and this
<br>0.625eV is what you read directly from the output, this Fermi energy
<br>should also be correct. If you are interested in the work function of<br>the (3,3)CNT you will have to obtain the difference between a vacuum<br>potential and the Fermi energy. In short the potential in the vacuum != 0
<br>due to the use of periodic boundary conditions. If you use pp.x to<br>obtain the potential remember that is is output in Rydbergs. This is all<br>discussed other times on the forum.<br><br>best of luck,<br><br>Nicholas
<br><br>On Thu, 10 Jan 2008, Zhu Xi wrote:<br><br>> Dear users,<br>><br>> I run a scf calculation of (3,3)CNT, but the fermi energy is 0.652eV, can<br>> anyone give some suggestion? thanks<br>><br>> ====================================================================================
<br>><br>> &control<br>> calculation='scf',<br>> PSEUDO_DIR='./',<br>> prefix='33',<br>> forc_conv_thr=1.0D-4,<br>> /<br>> &SYSTEM<br>
> ibrav = 0,<br>> celldm(1)= 18.8972612499,<br>> nat = 12,<br>> ntyp = 1,<br>> ecutwfc = 40.0 ,<br>> nosym = .true. ,<br>> nbnd = 48 ,<br>> occupations= 'smearing',degauss =
0.001<br>><br>> /<br>> &electrons<br>> conv_thr = 1.D-6,<br>> mixing_beta = 0.5D0,<br>> /<br>> CELL_PARAMETERS<br>> 1.0 0.000000000 0.000000000<br>> 0.000000000
1.0 0.000000000<br>> 0.000000000 0.000000000 0.245951<br>> ATOMIC_SPECIES<br>> C 12.00000 C.pz-vbc.UPF<br>> ATOMIC_POSITIONS (crystal)<br>> C 0.625289967 0.669611155 0.250000000
<br>> C 0.487077242 0.709466388 0.250000000<br>> C 0.291384631 0.523168925 0.250000000<br>> C 0.374710033 0.330388845 0.750000000<br>> C 0.512922758 0.290533612 0.750000000
<br>> C 0.708615369 0.476831075 0.750000000<br>> C 0.416429985 0.692001578 0.750000000<br>> C 0.675464001 0.616817067 0.750000000<br>> C 0.312292454 0.592869751 0.750000000
<br>> C 0.583570015 0.307998422 0.250000000<br>> C 0.324535999 0.383182933 0.250000000<br>> C 0.687707546 0.407130249 0.250000000<br>> K_POINTS automatic<br>> 1 1 11 0 0 0<br>
><br>> ==================================================<br>><br><br>*****************************************<br>Nicholas E. Singh-Miller<br>Ph.D. Candidate<br>Prof. Marzari Group (<a href="http://quasiamore.mit.edu" target="_blank">
quasiamore.mit.edu</a>)<br>Materials Science and Engineering<br>Massachusetts Institute of Technology<br>13-4066<br>(617)324-0372<br>*****************************************<br>_______________________________________________
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</a><br></blockquote>
</div><br><br clear="all"><br></div></div>-- <br><font color="#888888">X
</font><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>Hai-Ping Lan <br>Department of Electronics ,<br>Peking University , Bejing, 100871<br><a href="mailto:lanhaiping@gmail.com">
lanhaiping@gmail.com</a>, <a href="mailto:hplan@pku.edu.cn">hplan@pku.edu.cn</a>