vibrational analysis problem

yakutovich yakut... at gmail.com
Sun May 28 20:36:25 CEST 2017


Dear all,

I was trying to perform Vibrational Analysis for my system containing 590 
atoms.


&VIBRATIONAL_ANALYSIS
        DX  [bohr] 0.04
        NPROC_REP   288
        FULLY_PERIODIC  .TRUE.
        INTENSITIES  .TRUE.
    &PRINT
        &PROGRAM_RUN_INFO
        &END
        &MOLDEN_VIB
         FILENAME MOLVIB
        &END
    &END PRINT
&END VIBRATIONAL_ANALYSIS


For this calculation I fixed 324 atoms and let the other 266 to be 
optimized. 


&CONSTRAINT
   &FIXED_ATOMS
    LIST 1..324
   &END FIXED_ATOMS
  &END CONSTRAINT


However instead of 266*6 SCF cycles that I expected cp2k did more than 2500:


> grep "SCF WAVEFUNCTION OPTIMIZATION" *-r-*.out | wc -l
2520


At some point the execution reached the  WALLTIME 86000 and stopped. What 
surprised me again that cp2k was still able to compute the normal modes. *So 
my first question would be: can I trust the results of these calculations, 
taking into account that the last SCF cycles did not converge due to the 
time limit?*


In order to narrow down the problem I updated cp2k to the latest trunk 
version(svn:17932). Then I took a water molecule and slightly simplified 
the VIBRATIONAL_ANALYSIS section. Then I did the same calculations using 1 
and 2 replicas. It turned out that in the first case cp2k did 19 scf 
cycles, while in the second case 24. 

*So my second question: what cp2k is doing? is it a bug?**1 replica:*
VIB_no_intens_1replica> grep "SCF WAVEFUNCTION OPTIMIZATION" *-r-*.out | wc 
-l
19
VIB_no_intens_1replica> grep "VIB| REPLI" out | wc -l
18

*2 replicas:*
....VIB_no_intens_2replicas> grep "VIB| REPLI" out | wc -l
18
....VIB_no_intens_2replicas> grep "SCF WAVEFUNCTION OPTIMIZATION" *-r-*.out 
| wc -l
24


I attached the compressed running directories for the both water cases. I 
would appreciate any help.

Best regards,
Sasha

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