Hello, all:<br><br>I'm trying to do a variable cell geometry optimization of a carbon nanotube with "pw.x". My input follows:<br><br>---------------------------------------------------------------------------------------<br><br> &CONTROL<br>                       title = 'nanotubo' ,<br>                 calculation = 'vc-relax' ,<br>                restart_mode = 'from_scratch' ,<br>                  wf_collect = .true. ,<br>                      outdir = '~/pw-calc/nanotubos/8x0/outdir/'
 ,<br>                      wfcdir = '~/pw-calc/nanotubos/8x0/wfcdir/' ,<br>                  pseudo_dir = '~/pw-calc/pseudo/' ,<br>                      prefix = 'nanotubo' ,<br>                     disk_io = 'default' ,<br>                   verbosity = 'default' ,<br>               etot_conv_thr = 1D-8 ,<br>               forc_conv_thr = 1D-4
 ,<br>               ekin_conv_thr = 1D-4 ,<br>                       nstep = 200 ,<br> /<br> &SYSTEM<br>                       ibrav = 8,<br>                           A = 4.32 ,<br>                           B = 13.00 ,<br>                           C = 16.0
 ,<br>                         nat = 64,<br>                        ntyp = 1,<br>                     ecutwfc = 40.0 ,<br> /<br> &ELECTRONS<br>            electron_maxstep = 100,<br>                    conv_thr = 1D-4 ,<br>             diagonalization = 'cg' ,<br>            diago_cg_maxiter =
 200,<br> /<br> &IONS<br>                ion_dynamics = 'damp' ,<br> /<br> &CELL<br>               cell_dynamics = 'damp-pr' ,<br>                       wmass = 400 ,<br> /<br>ATOMIC_SPECIES<br>    C   12.01070  C.pbe.uspp <br>ATOMIC_POSITIONS angstrom <br>    C     0.0000000     0.0000000     3.1756544<br>    C     0.7200000     1.2152703     2.9339221<br>    C     0.0000000     2.2455268     2.2455268<br>   
 C     0.7200000     2.9339221     1.2152703<br>    C     0.0000000     3.1756544     0.0000000<br>    C     0.7200000     2.9339221     1.2152703<br>    C     0.0000000     2.2455268     2.2455268<br>    C     0.7200000     1.2152703     2.9339221<br>    C     0.0000000     0.0000000     3.1756544<br>    C     0.7200000    -1.2152703     2.9339221<br>    C     0.0000000    -2.2455268    
 2.2455268<br>    C     0.7200000    -2.9339221     1.2152703<br>    C     0.0000000    -3.1756544     0.0000000<br>    C     0.7200000    -2.9339221     1.2152703<br>    C     0.0000000    -2.2455268     2.2455268<br>    C     0.7200000    -1.2152703     2.9339221<br>    C     2.1600000     1.2152703     2.9339221<br>    C     2.8800000     2.2455268     2.2455268<br>    C     2.1600000     2.9339221    
 1.2152703<br>    C     2.8800000     3.1756544     0.0000000<br>    C     2.1600000     2.9339221     1.2152703<br>    C     2.8800000     2.2455268     2.2455268<br>    C     2.1600000     1.2152703     2.9339221<br>    C     2.8800000     0.0000000     3.1756544<br>    C     2.1600000    -1.2152703     2.9339221<br>    C     2.8800000    -2.2455268     2.2455268<br>    C     2.1600000   
 -2.9339221     1.2152703<br>    C     2.8800000    -3.1756544     0.0000000<br>    C     2.1600000    -2.9339221     1.2152703<br>    C     2.8800000    -2.2455268     2.2455268<br>    C     2.1600000    -1.2152703     2.9339221<br>    C     2.8800000     0.0000000     3.1756544<br>    C     4.3200000     2.2455268     2.2455268<br>    C     5.0400000     2.9339221     1.2152703<br>    C    
 4.3200000     3.1756544     0.0000000<br>    C     5.0400000     2.9339221     1.2152703<br>    C     4.3200000     2.2455268     2.2455268<br>    C     5.0400000     1.2152703     2.9339221<br>    C     4.3200000     0.0000000     3.1756544<br>    C     5.0400000    -1.2152703     2.9339221<br>    C     4.3200000    -2.2455268     2.2455268<br>    C     5.0400000    -2.9339221     1.2152703<br>   
 C     4.3200000    -3.1756544     0.0000000<br>    C     5.0400000    -2.9339221     1.2152703<br>    C     4.3200000    -2.2455268     2.2455268<br>    C     5.0400000    -1.2152703     2.9339221<br>    C     4.3200000     0.0000000     3.1756544<br>    C     5.0400000     1.2152703     2.9339221<br>    C     6.4800000     2.9339221     1.2152703<br>    C     7.2000000     3.1756544     0.0000000<br>   
 C     6.4800000     2.9339221     1.2152703<br>    C     7.2000000     2.2455268     2.2455268<br>    C     6.4800000     1.2152703     2.9339221<br>    C     7.2000000     0.0000000     3.1756544<br>    C     6.4800000    -1.2152703     2.9339221<br>    C     7.2000000    -2.2455268     2.2455268<br>    C     6.4800000    -2.9339221     1.2152703<br>    C     7.2000000    -3.1756544     0.0000000<br>   
 C     6.4800000    -2.9339221     1.2152703<br>    C     7.2000000    -2.2455268     2.2455268<br>    C     6.4800000    -1.2152703     2.9339221<br>    C     7.2000000     0.0000000     3.1756544<br>    C     6.4800000     1.2152703     2.9339221<br>    C     7.2000000     2.2455268     2.2455268          <br>K_POINTS automatic <br>  8 1 1   0 0 0 <br><br>---------------------------------------------------------------------------------------<br><br>With this input, I'm getting the following error
 message:<br><br>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br>     from setup : error #         1<br>     Wrong atomic coordinates <br> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br><br>What's going on?<br><br>Regards,<br><br>Roberto<br><br><br><p>
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