Stuck when using BFGS

[ma455...@gmail.com]

Hi,

I'm a new user of cp2k v8.2. When I do GEO_OPT using BFGS, it has been stuck many times in the step "OPTIMIZATION STEP: 1" as shown below without showing any errors. If I don't kill the job manually, the job will just keep running without printing any new results. This does not occurs when using SCALAPACK instead of ELPA or using LBFGS/CG instead of BFGS. I'm wondering is there any way to solve this BFGS issue? Thanks.

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Regards,

Hongyang

[Krack Matthias (PSI)]

Hi

 

It seems that is an issue rather related to ELPA than to BFGS. specifically, because BFGS involves a diagonalization of the Hessian whereas LBFGS does not. When BFGS works with ScaLAPACK, the problem stems most likely from ELPA. There have been issues observed with CP2K/ELPA, recently. So, just use ScaLAPACK, since the advantage of using ELPA instead of ScaLAPACK is most likely minor for your case.

 

M.

 

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[ma455...@gmail.com]

Hi Matt,

Got it. Although I do like using ELPA because it is much faster. Thank you very much. Wish ELPA would be more compitable with cp2k in the future (figure crossed).

Regards,

Hongyang

[fabia...@gmail.com]

Hi

If you compile cp2k yourself you can modify the code to force BFGS to select SCALAPACK and still use ELPA for everything else. In src/motion/bfgs_optimizer.F replace every occurence of "choose_eigv_solver" with "cp_fm_syevd".

If you are in the cp2k root directory simply run

sed -i.bak src/motion/bfgs_optimizer.F 's/choose_eigv_solver/cp_fm_syevd/g'

and recompile the code. This works for me but I have not extensively tested it.

Cheers

Fabian

[ma455...@gmail.com]

Hi Fabian,

Thanks for the information! I will give it a try.

Cheers,

Hongyang