Why can't cell optimization converge?

[Matthias Krack]

Dear Enlong,,

I would suggest to use BFGS (or LBFGS for large systems) instead of CG. 
Moreover, you may change the PRINT_LEVEL to medium to get more info. 
However, even if the run will converge somehow, the results won't be 
reasonable given the cell size of only 2.5A in z direction in a gamma point 
calculation.

Matthias

On Monday, March 3, 2014 10:41:11 AM UTC+1, Enlong Liu wrote:
>
> Fellows,
>
> I am practicing CP2K by doing cell optimization and geometry optimization 
> to CNT. In the cell_opt, I choose 'DIRECT_CELL_OPT*: Performs a geometry 
> and cell optimization at the same time. The stress tensor is computed at 
> every step* '. And the max SCF iteration is 1000. However, every time I 
> run the program, the program always used all 1000 iteration to get the 
> result, which in my opinion, means the result does not converge. It seems 
> like for every step, the threshold for energy is satisfied but between 
> steps the threshold for geometry can not be satisfied. Could you help me to 
> solve this issue?
>
> PS: the input file is in the attachment.
>
> Thanks a lot for your help!
>
> Best regards,
> Enlong
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20140303/a8162127/attachment.htm>