Andrea and Giovanni,<div><br></div><div>Thank you for your comments. Yes, it was a mistake to have this subtle difference between the lattice vectors. I changed them to be identical:</div><div><br></div><div><div>CELL_PARAMETERS</div>
<div>5.42763 0.0 0.0</div><div>0.0 5.42763 0.0</div><div>0.0 0.0 5.42763</div><div><br></div><div>Now pw.x can run in high verbosity without crashing, and the phonon run proceeds, but there is clearly still a symmetry problem as it gives '?' for many of the modes in the symmetry analysis.</div>
<div><br></div><div><div> Mode symmetry, C_3v (3m) point group:</div><div><br></div><div> omega( 1 - 1) = -336.3 [cm-1] --> ?</div><div> omega( 2 - 2) = -336.3 [cm-1] --> ?</div>
<div> omega( 3 - 3) = -336.3 [cm-1] --> ?</div><div> omega( 4 - 4) = -336.3 [cm-1] --> ?</div><div> omega( 5 - 5) = -336.3 [cm-1] --> ?</div><div> omega( 6 - 6) = -336.3 [cm-1] --> ?</div>
<div> omega( 7 - 7) = 26.1 [cm-1] --> ?</div><div> omega( 8 - 8) = 26.2 [cm-1] --> ?</div><div> omega( 9 - 9) = 26.2 [cm-1] --> ?</div><div> omega( 10 - 10) = 286.6 [cm-1] --> ?</div>
<div> omega( 11 - 11) = 286.6 [cm-1] --> ?</div><div> omega( 12 - 12) = 287.0 [cm-1] --> ?</div><div> omega( 13 - 13) = 287.1 [cm-1] --> ?</div><div> omega( 14 - 14) = 287.5 [cm-1] --> ?</div>
<div> omega( 15 - 15) = 288.1 [cm-1] --> ?</div><div> omega( 16 - 16) = 413.2 [cm-1] --> A_1 L_1 I+R</div><div> omega( 17 - 17) = 413.2 [cm-1] --> A_2 L_2 </div>
<div> omega( 18 - 19) = 413.2 [cm-1] --> E L_3 I+R</div><div> omega( 20 - 21) = 413.3 [cm-1] --> E L_3 I+R</div><div> omega( 22 - 22) = 583.3 [cm-1] --> A_1 L_1 I+R</div>
<div> omega( 23 - 24) = 583.3 [cm-1] --> E L_3 I+R</div></div><div><br></div><div><br></div><div>David Strubbe</div><div>MIT</div><div><br><div><br><div class="gmail_quote">On Wed, Jan 16, 2013 at 2:10 AM, Dal Corso Andrea <span dir="ltr"><<a href="mailto:dalcorso@sissa.it" target="_blank">dalcorso@sissa.it</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="HOEnZb"><div class="h5">On Tue, 2013-01-15 at 18:10 -0500, David Strubbe wrote:<br>
> Dear QE developers,<br>
><br>
><br>
> I have encountered an internal error regarding symmetry with QE 5.0.2,<br>
> for a calculation with 8 atoms of Si. The scf calculation with pw.x<br>
> runs fine, but then ph.x crashes immediately with the following<br>
> message. This happened in serial and parallel with ifort, as well as<br>
> in serial with gfortran. Input files <a href="http://scf.in" target="_blank">scf.in</a> and <a href="http://ph.in" target="_blank">ph.in</a> are below also.<br>
> I tried with the patch to 5.0.3 emailed out by Dr. Gianozzi a few<br>
> weeks, and got the same error.<br>
><br>
><br>
> David Strubbe<br>
> MIT<br>
><br>
><br>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br>
> %%%%%%%%%<br>
> Error in routine divide_class (1):<br>
> Wrong classes for C_3v<br>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br>
> %%%%%%%%%<br>
><br>
><br>
> $ cat <a href="http://scf.in" target="_blank">scf.in</a><br>
> &control<br>
> prefix = 'silicon'<br>
> calculation = 'scf'<br>
> restart_mode = 'from_scratch'<br>
> pseudo_dir = '/home/dstrubbe/raman_Si/pseudo'<br>
> /<br>
> &system<br>
> ibrav = 0<br>
> celldm(1) = 1.88972613<br>
> nat = 8<br>
> ntyp = 1<br>
> nbnd = 32<br>
> ecutwfc = 50.0<br>
> /<br>
> &electrons<br>
> /<br>
> CELL_PARAMETERS<br>
> 5.427632 0.0 0.0<br>
> 0.0 5.42763 0.0<br>
> 0.0 0.0 5.42763<br>
<br>
<br>
</div></div>This is a well known problem. pw.x finds more symmetries than the<br>
routines that analyze the point group. This happens because the<br>
difference between 5.427632 and 5.42763 is too small and pw.x finds<br>
symmetries that are not there. If this is a mistake in your input than<br>
please correct it an use three equal values, if instead this is really<br>
what you want, than the threshold for comparing symmetries (accept<br>
parameter in symm_base module) should be decreased, otherwise pw.x<br>
ignore the difference in any case.<br>
<br>
<br>
HTH,<br>
<br>
Andrea<br>
<div class="im HOEnZb"><br>
<br>
<br>
<br>
<br>
> ATOMIC_SPECIES<br>
> Si 28.086 Si.UPF<br>
> ATOMIC_POSITIONS angstrom<br>
> Si 0.542763 0.542763 0.542763<br>
> Si 3.256579 3.256579 0.542763<br>
> Si 0.542763 3.256579 3.256579<br>
> Si 3.256579 0.542763 3.256579<br>
> Si 1.899671 1.899671 1.899671<br>
> Si 4.613487 4.613487 1.899671<br>
> Si 1.899671 4.613487 4.613487<br>
> Si 4.613487 1.899671 4.613487<br>
> K_POINTS automatic<br>
> 1 1 1 0 0 0<br>
><br>
><br>
> $ cat <a href="http://ph.in" target="_blank">ph.in</a><br>
> phonons of Si at Gamma<br>
> &inputph<br>
> tr2_ph=1.0d-12,<br>
> prefix='silicon',<br>
> epsil=.true.,<br>
> trans=.true.,<br>
> amass(1)=28.0855,<br>
> /<br>
> 0.0 0.0 0.0<br>
><br>
><br>
</div><div class="HOEnZb"><div class="h5">> _______________________________________________<br>
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</div></div></blockquote></div><br></div></div></div>