<div dir="ltr"><div><div><div><div><div><div><div>Dear Espresso community<br><br></div>I have one problem
that is important for me; it is somewhat surprising. I run
geometry optimization (relax) calculations with pw.x with identical input files,
and I obtain rather different final coordinates. The problem does not
happen if ecutwfc is 30, but it does appear for cutoffs of 60, 80 or 90. Below one can see the exact input file, and examples of the difference
between the final coordinates for both runs (both run with identical
input) for given cutoffs. <br><br></div>Could anybody give me a clue on the origin of the problem, and how to solve it?<br><br></div>Thank you very much. Best regards.<br clear="all"><br><br><br>
<p class="MsoNormal"><span style="color:black" lang="EN-US">Input
file:</span></p>
<p class="MsoNormal"><span style="color:black" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">&CONTROL</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>calculation = 'relax',</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>restart_mode = 'from_scratch',</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>prefix='',</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>outdir = './',</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>pseudo_dir =
'/path_xxx/PP/',</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>forc_conv_thr = 1.0D-6 ,</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>etot_conv_thr = 1.0D-8 ,</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>/</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">&system</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>ibrav = 0, a=18.0, </span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>nat= 26, ntyp= 2,</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>ecutwfc = 30d0,</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>nbnd = 100, </span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">/</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">&electrons</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>conv_thr = 1.0e-9,</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>mixing_beta = 0.7,</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>mixing_mode = 'plain',</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>diagonalization = 'cg'</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">/</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">&IONS</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">/</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">ATOMIC_SPECIES</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">C<span> </span>12.0107<span> </span>C.pz-vbc.UPF</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>1.007825035<span> </span>H.pz-vbc.UPF</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">ATOMIC_POSITIONS { angstrom }</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">C<span> </span>8.891700e+00<span> </span>8.891700e+00<span> </span>8.891700e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">C<span> </span>9.783400e+00<span> </span>9.783400e+00<span> </span>8.000000e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">C<span> </span>9.783400e+00<span> </span>8.000000e+00<span> </span><span> </span>9.783400e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">C<span> </span>8.000000e+00<span> </span>9.783400e+00<span> </span>9.783400e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">C<span> </span>8.891700e+00<span> </span>1.067510e+01<span> </span>1.067510e+01</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">C<span> </span>1.067510e+01<span> </span>1.067510e+01<span> </span>8.891700e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">C<span> </span>1.067510e+01<span> </span>8.891700e+00<span> </span>1.067510e+01</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">C<span> </span>9.783400e+00<span> </span>1.156680e+01<span> </span>9.783400e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">C<span> </span>9.783400e+00<span> </span>9.783400e+00<span> </span>1.156680e+01</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">C<span> </span>1.156680e+01<span> </span>9.783400e+00<span> </span>9.783400e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>8.391700e+00<span> </span>8.391700e+00<span> </span>8.391700e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>7.500000e+00<span> </span>1.028340e+01<span> </span>9.283400e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>7.500000e+00<span> </span>9.283400e+00<span> </span>1.028340e+01</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>9.283400e+00<span> </span>1.028340e+01<span> </span>7.500000e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>1.028340e+01<span> </span>9.283400e+00<span> </span>7.500000e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>9.283400e+00<span> </span>7.500000e+00<span> </span>1.028340e+01</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>1.028340e+01<span> </span>7.500000e+00<span> </span>9.283400e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>9.283400e+00<span> </span>1.206680e+01<span> </span>9.283400e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>1.206680e+01<span> </span>9.283400e+00<span> </span>9.283400e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>9.283400e+00<span> </span>9.283400e+00<span> </span>1.206680e+01</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>8.391700e+00<span> </span>1.117510e+01<span> </span>1.117510e+01</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>1.117510e+01<span> </span>1.117510e+01<span> </span>8.391700e+00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>1.117510e+01<span> </span>8.391700e+00<span> </span>1.117510e+01</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>1.028340e+01<span> </span>1.206680e+01<span> </span>1.028340e+01</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>1.028340e+01<span> </span>1.028340e+01<span> </span>1.206680e+01</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">H<span> </span>1.206680e+01<span> </span>1.028340e+01<span> </span>1.028340e+01</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">CELL_PARAMETERS {cubic}</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>1.00<span> </span>0.00<span>
</span>0.00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>0.00<span> </span>1.00<span>
</span>0.00</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"><span> </span>0.00<span> </span>0.00<span>
</span>1.00 </span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">K_POINTS {gamma} {automatic}</span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">1 1 1<span> </span>0 0 0</span></p>
<p class="MsoNormal"><span style="color:black" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="color:black" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="color:black" lang="EN-US">The
program is run with</span></p>
<p class="MsoNormal"><span style="color:black" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family:courier;color:black" lang="EN-US">mpirun -np 32 /path_xxx/pw.x</span><span style="color:black" lang="EN-US"></span></p>
<br><br></div>Final coordinates: The first two rows for ecutwfc=30 for two runs with identical input are:<br><br></div>ATOMIC_POSITIONS (angstrom)<br></div>C 8.898432121 8.898432121 8.898432121 </div>C 9.783306562 9.783306562 8.01967010<span style="background-color:rgb(0,255,0)"><b>7</b></span><div><div><br>ATOMIC_POSITIONS (angstrom)<br>C 8.898432121 8.898432121 8.898432121 <br>C 9.783306562 9.783306562 8.01967010<span style="background-color:rgb(0,255,0)"><b>9</b></span><br><div><div><br><br>Final coordinates: The first two rows for ecutwfc=60 for two runs with identical input are:<br><br>ATOMIC_POSITIONS (angstrom)<br>C 8.9049<span style="background-color:rgb(255,0,0)">88579</span> 8.9049<span style="background-color:rgb(255,0,0)">88579</span> 8.9049<span style="background-color:rgb(255,0,0)">88579</span> <br>C 9.78342<span style="background-color:rgb(255,0,0)">6086 </span>9.78342<span style="background-color:rgb(255,0,0)">6086</span> 8.0318<span style="background-color:rgb(255,0,0)">09869</span><span style="background-color:rgb(255,0,0)"></span><br><br>ATOMIC_POSITIONS (angstrom)<br>C 8.9049<span style="background-color:rgb(255,0,0)">62246</span> 8.9049<span style="background-color:rgb(255,0,0)">62246</span> 8.9049<span style="background-color:rgb(255,0,0)">62246</span><br>C 9.78342<span style="background-color:rgb(255,0,0)">5401 </span>9.78342<span style="background-color:rgb(255,0,0)">5401 </span> 8.0318<span style="background-color:rgb(255,0,0)">47251</span><span style="background-color:rgb(0,255,0)"></span><br><br>-- <br><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr">--<br><br>Dr. Pablo García Risueño<br><br>Institut für Physikalische Chemie, Universität Hamburg, Grindelallee 117, 20146 Hamburg<br><br>Tel. +49 040 42 83 84 82 7</div></div></div></div></div></div>
</div></div></div></div></div>