CUTOFF convergence problem

[Guanna Li]

I reported my test results here:
https://groups.google.com/forum/#!topic/cp2k/UYaBsH6A7e0

All single point calculations used the same input structure. But you can 
see the enerny didn't converge even the CUTOFF value is big. 
 

On Monday, November 9, 2015 at 4:33:32 PM UTC+1, katarína stančiaková wrote:
>
> Dear CP2K users,
> I am running my calculations and I have CUTOFF convergence problem - in 
> fact I can not see any convergence in the total energy. I know that the 
> relative differences in energies are important (not the absolute values of 
> energies), therefore I am comparing the energy differences between two 
> structures (I am working with zeolites, and my two structures differs in 
> the position of hydrogen). Even with very high cutoff values I can not 
> observe any convergence of the total energies as well as energy differences.
> Do you have any idea where is the problem? I will be thankful for any help!
>
> Here are my data:
>
> CUTOFF [Ry]            Total Energy [a.u.]
>                                 structure 1                structure 2
> 600                           -3467.0403965424    -3467.0619253888
> 800                           -3467.0521866655    -3467.0622253178
> 1000                         -3467.0838714739    -3467.1096147317
> 1200                         -3467.0833499728    -3467.1103018678
> 1400                         -3467.0975445683    -3467.1102723936
>
>
> ENERGY DIFFERENCES
>
>
> CUTOFF [Ry]    E_str1 - E_str2 [kJ/mol]    
>
> 600                55.9750007029
> 800                26.1004960059
> 1000              66.932470253
> 1200              70.0749269477
> 1400              33.0923456248
>     
> Thank you
> Katarina
>
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