<div class="gmail_quote"><div class="gmail_quote"><div><div></div><div class="h5"><br>Hi everyone,<br>     I have a question. When I put my atom positions unde .xyz file, and input into xcrysden, they will generate a round carbon nanotube . However, when I put the same atomic positions under <a href="http://scf.in" target="_blank">scf.in</a> file, and then input them into xcrysden, I got departed four parts like four quarters of a nanotube, all outwards. I feel very stange about this. Can anyone tell me is there anything wrong with the scf file? I want a round carbon nanotube because it is more vivid and instinctive.<br>


   my input files are like this:<br><br>    &CONTROL<br>                 calculation = 'scf' ,<br>                restart_mode = 'from_scratch' ,<br>                      outdir = '/home/mems/espresso-4.2/tmp/' ,<br>


                  pseudo_dir = '/home/mems/espresso-4.2/pseudo/' ,<br>                      prefix = 'cnt' ,<br> /<br> &SYSTEM<br>                       ibrav = 6,<br>                   celldm(1) = 21.764541128,celldm(3)=0.213765379<br>


                         nat = 24,<br>                        ntyp = 1,<br>                     ecutwfc = 75 ,<br> /<br> &ELECTRONS<br>                    conv_thr = 1.0d-8 ,<br>                 mixing_beta = 0.7 ,<br>


 /<br>ATOMIC_SPECIES<br>    C   12.01100  C.pz-vbc.UPF <br>ATOMIC_POSITIONS angstrom<br>  C        4.085165     -0.000000   -1.231010<br>  C        3.838021     1.399343    -1.231010<br>  C        3.537856     2.042582     0.000000<br>


  C        2.624152     3.130877     0.000000<br>  C        2.042582     3.537856    -1.231010<br>  C        0.707144     4.023496    -1.231010<br>  C        0.000000     4.085165     0.000000<br>  C       -1.399343     3.838021     0.000000<br>


  C       -2.042582     3.537856    -1.231010<br>  C       -3.130877     2.624152    -1.231010<br>  C       -3.537856     2.042582     0.000000<br>  C       -4.023496     0.707144     0.000000<br>  C       -4.085165     0.000000    -1.231010<br>


  C       -3.838021    -1.399343    -1.231010<br>  C       -3.537856    -2.042582     0.000000<br>  C       -2.624152    -3.130877     0.000000<br>  C       -2.042582    -3.537856    -1.231010<br>  C       -0.707144    -4.023496    -1.231010<br>


  C       -0.000000    -4.085165     0.000000<br>  C        1.399343    -3.838021     0.000000<br>  C        2.042582    -3.537856    -1.231010<br>  C        3.130877    -2.624152    -1.231010<br>  C        3.537856    -2.042582     0.000000<br>


  C        4.023496    -0.707144     0.000000<br><br>K_POINTS automatic <br>  4 4 4   1 1 1 <br><br>and my .xyz file are like <br>24<br>(6,6) Nanotube -- TubeGen 3.3, J T Frey, University of Delaware<br>  C        4.085165    -0.000000    -1.231010<br>


  C        3.838021     1.399343    -1.231010<br>  C        3.537856     2.042582     0.000000<br>  C        2.624152     3.130877     0.000000<br>  C        2.042582     3.537856    -1.231010<br>  C        0.707144     4.023496    -1.231010<br>


  C        0.000000     4.085165     0.000000<br>  C       -1.399343     3.838021     0.000000<br>  C       -2.042582     3.537856    -1.231010<br>  C       -3.130877     2.624152    -1.231010<br>  C       -3.537856     2.042582     0.000000<br>


  C       -4.023496     0.707144     0.000000<br>  C       -4.085165     0.000000    -1.231010<br>  C       -3.838021    -1.399343    -1.231010<br>  C       -3.537856    -2.042582     0.000000<br>  C       -2.624152    -3.130877     0.000000<br>


  C       -2.042582    -3.537856    -1.231010<br>  C       -0.707144    -4.023496    -1.231010<br>  C       -0.000000    -4.085165     0.000000<br>  C        1.399343    -3.838021     0.000000<br>  C        2.042582    -3.537856    -1.231010<br>


  C        3.130877    -2.624152    -1.231010<br>  C        3.537856    -2.042582     0.000000<br>  C        4.023496    -0.707144     0.000000<br><br></div></div>-------<br>Chengyu Yang<br>Graduate student<br>Material Science and Engineering.<br>

U of Central Florida<br><br><a href="mailto:Chengyu.young@gmail.com" target="_blank">Chengyu.young@gmail.com</a> <br>
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