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

Stephen Vicchio svi... at g.clemson.edu
Sat Feb 15 16:05:34 UTC 2020

Is there a keyword to set the parallelization for these vibrational jobs? I 
ran a small vibrational calculation (19 single point calculations) the 
other day and I had to select 360 GB on 20 cores because I only had one 
group. Does CP2K set the number of groups or the group size? I checked your 
.inp file, but I didn't see any input parameter that controls that setup. 

Also, sorry to diverge from your initial question! This was a question I 
had a few days ago. 


On Saturday, February 15, 2020 at 10:56:38 AM UTC-5, Torstein Fjermestad 
> They are parallelized in six groups. 
> each group run on 144 cores (NPROC_REP  144)
> lørdag 15. februar 2020 16.29.26 UTC+1 skrev Stephen Vicchio følgende:
>> 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)?
>> Stephen 
>> 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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