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<p>Dear QE users/developers,</p>
<p>Following from the previous request, I've changed to a newer MPI library which gives a little more error information, specifically it does now crash with the following message:</p>
<p>An error occurred in MPI_Allreduce<br />eported by process [1564540929,0]<br />on communicator MPI COMMUNICATOR 6 SPLIT FROM 3<br />MPI_ERR_TRUNCATE: message truncated<br />MPI_ERRORS_ARE_FATAL (processes in this communicator will now abort, and potentially your MPI job)</p>
<p>It appears that this is thrown at the end of a self-consistent DFPT calculation (see the attached output file - it appears the final iteration has converged). I'm using the development version of QE, so I suspect that the error arises from somewhere inside <a href="https://gitlab.com/QEF/q-e/-/blob/develop/PHonon/PH/solve_linter.f90">https://gitlab.com/QEF/q-e/-/blob/develop/PHonon/PH/solve_linter.f90</a>.</p>
<p>I don't really know how to debug/workaround this further, any ideas/suggestions would be most welcome.</p>
<p>Best,</p>
<p>Michael Hutcheon</p>
<p>TCM group, University of Cambridge</p>
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<p id="reply-intro">On 2020-05-12 13:29, M.J. Hutcheon wrote:</p>
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<p>Dear QE users/developers,</p>
<p>I am running an electron-phonon coupling calculation at the gamma point for a large unit cell Calcium-Hydride (Output file attached). The calculation appears to get stuck during the DFPT stage. It does not crash, or produce any error files/output of any sort, or run out of walltime, but the calculation does not progress either. I have tried different parameter sets (k-point grids + cutoffs), which changes the representation where the calculation gets stuck, but it still gets stuck. I don't really know what to try next, short of compiling QE in debug mode and running under a debugger to see where it gets stuck. Any ideas before I head down this laborious route?</p>
<p>Many thanks,</p>
<p>Michael Hutcheon</p>
<p>TCM group, University of Cambridge</p>
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