[CP2K-user] A single point calculation fails in a vibrational analysis

Stephen Vicchio svi... at g.clemson.edu
Sat Feb 15 15:29:26 UTC 2020

Thanks for sharing some of your insights/problems! I am curious as well. 
Also, do the 1735 single point calculations run simultaneously 
(parallelized)? Or are they performed sequentially (in series)?


On Saturday, February 15, 2020 at 10:27:10 AM UTC-5, Matt W wrote:
> Maybe printing forces leads to you running out of disk space or a similar 
> file system problem? It won't be affecting the actual calculation.
> Matt
> On Saturday, February 15, 2020 at 3:16:13 PM UTC, Torstein Fjermestad 
> wrote:
>> Just a small update:
>> The vibrational analysis calculation completed successfully when I 
>> changed the section parameter of &FORCES in the &PRINT section of 
>> &FORCE_EVAL from ON to SILENT. This was the only thing that changed. Here 
>> is the output of the "diff" command on the two input files:
>> <      &FORCES  ON
>> ---
>> >      &FORCES  SILENT
>> This was surprising to me because I thought the &PRINT section determined 
>> what is printed and had no influence on the outcome of the calculation. 
>> Could it be a bug? I have been using CP2K version 7.0 
>> the output of the command cp2k.popt -v:
>>  CP2K version 7.0 (Development Version)
>>  SVN source code revision
>>  cp2kflags: fftw3 parallel mpi3 scalapack libderiv_max_am1=4 
>> libint_max_am=5 mkl
>> Regards,
>> Torstein
>> fredag 14. februar 2020 11.45.34 UTC+1 skrev Torstein Fjermestad følgende:
>>> Dear all, 
>>> I started a vibrational analysis calculation on a system that consists 
>>> of 289 atoms, and therefore 2*3*289+1 = 1735 single point calculations are 
>>> necessary to complete the vibrational analysis (The input file is 
>>> attached). After having completed 708 single point calculations, the 
>>> vibrational analysis stopped because one single point calculation failed.
>>> The error message I got was the following:
>>> "Cholesky decomposition failed. Matrix ill conditioned ?"
>>> While this isolated problem seems to have a straight-forward solution 
>>> (for instance by following the advice provided here: 
>>> https://www.cp2k.org/faq:cholesky_decomp_failed), it seems to be a bit 
>>> more complicated in the context of a vibrational analysis. 
>>> There are two reasons why I think it would be more complicated. These 
>>> are the following:
>>>    1. The geometry for which the energy calculation failed is not 
>>>    printed (at least I cannot see it). Only the geometries for which the 
>>>    energy converged are printed. This makes it difficult (impossible) to 
>>>    troubleshoot the problem of why the energy calculation of that structure 
>>>    failed. Is it possible to change the print settings such that the structure 
>>>    is printed before the energy calculation starts?
>>>    2. Suppose that I will be able to compute the energy for the 
>>>    particular geometry. Is it then possible to restart the vibrational 
>>>    analysis from the point where it failed, or do I have to start all over 
>>>    again from the beginning? 
>>> The input file and the output file with the error message are attached. 
>>> Thanks a lot for your help. 
>>> Regards,
>>> Torstein Fjermestad
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