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<p>Dear Ruochen Shi,</p>
<p>A segmentation fault generally does not occur because of lack of
available memory. In that case, you would see an error like "out
of memory, killed", or "killed (signal 9)" - the details of which
depend on your OS, MPI library, and possibly scheduler.</p>
<p>Segmentation faults instead occur when a program tries to access
memory that it is not allowed to - because it is not allocated for
this process, see <a moz-do-not-send="true"
href="https://en.wikipedia.org/wiki/Segmentation_fault">https://en.wikipedia.org/wiki/Segmentation_fault</a></p>
<p>In general this is a "program error", meaning there is a fault in
your compiled executable. This does <i>not</i> necessarily mean
that it is a problem with Quantum ESPRESSO - in fact, most of
these problems occur due to bugs in the underlying (MPI, BLAS,
FFT) libraries or how they were compiled and linked.</p>
<p>Since there are a million places in which a segfault can occur,
it is basically impossible to debug remotely. Your options are:</p>
- try running the QE test suite. If you see segfaults there, it is
almost guaranteed to be a library / compilation issue<br>
- compile the code with lower optimization level, enabling debug
statements, bounds checking, ...<br>
- make sure the libraries used are compiled and linked correctly, or
try using different ones<br>
- use a debugger, like gdb. This article <a moz-do-not-send="true"
href="https://www.cprogramming.com/debugging/segfaults.html">https://www.cprogramming.com/debugging/segfaults.html</a>
might be a decent introduction
<p>Best regards,</p>
<p>Dominik Gresch</p>
<p>---</p>
<p>Simulation Engineer, Microsoft Quantum<br>
</p>
<div class="moz-cite-prefix">On 20.05.20 18:04, 时若晨 wrote:<br>
</div>
<blockquote type="cite"
cite="mid:5b15e9c3.9d3e.17232d3fca0.Coremail.1801110162@pku.edu.cn">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<p style="font-family:SimSun;"> Dear all,
</p>
<p style="font-family:SimSun;"> I'm a new user to
quantum-espresso, and recently i've encontered a problem when
calculating phonon frequency in a heterojunction structure
containing 24 atoms in an unit cell. A "<span
style="font-family:SimSun;">forrtl: severe (174): SIGSEGV,
segmentation fault occurred</span>" error happens, which is
frequently asked by users. I suppose this is beacause there's
too many atoms in the unit cell, such that RAM need excesses the
RAM provided, since I ran a calculation on a similiar structure
but whit 12 atoms in the unit cell, and it ran all very well.
The self-consistence-field calculation for this structure ran
well,too. I've tried some ways, such as set 'verbosity' in the
ph.in file to 'minimal', and add '<span
style="color:#3D464D;font-family:-apple-system,
"Helvetica Neue", Helvetica, Arial, "PingFang
SC", "Hiragino Sans GB", "WenQuanYi Micro
Hei", "Microsoft Yahei",
sans-serif;white-space:normal;">ulimit -s unlimited</span>' in
the .bashrc. However, no one works.
</p>
<p style="font-family:SimSun;"> So I wonder is there a way to
overcome this problem?
</p>
<p style="font-family:SimSun;"> My input and output file for scf
and ph at Gamma point is attached. The text for error is also
attatched.
</p>
<p style="font-family:SimSun;"> <br>
</p>
<p style="font-family:SimSun;"> Ruochen Shi
</p>
<br>
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