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

[Torstein Fjermestad]

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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