[CP2K-user] [CP2K:14388] Struggling with getting converge for Zr(110) optimisation

[Lucas Lodeiro]

Hi Ohaya,

As Matthias said, your SIGMA value is too small, if you use 0.2eV in VASP,
you have to set 2320K in CP2K, and add more orbitals... and if you delete
the CHOLESKY INVERSE line you could get a speed up of 10 %.
Also there are a lot of convergence criteria which are so different between
the programs... for example the EDIFF in VASP is 1.0E-4 related to the
energy, meanwhile in CP2K the EPS_SCF is 1.0E-5 related to the
coefficients of the density matrix... probably with it you are getting more
converged energies with CP2K, and this requires more scf cycles.
Just to mention it, for the GEO_OPT, CP2K uses 4 criterias (energy, forces)
and VASP uses just one, EDIFFG, the energy or the force... This
probably ensures better converged structures in CP2K too.

If you want to compare both programs, you have to check all these criteria,
and match them to compare more precisely.

Finally, you use LBFGs instead of BFGs... I do not know if changing it you
get a speed up in the ionic relaxation, but the manual says that LBFGs is
for big systems, and yours is small.

Regards
Lucas Lodeiro

El dom, 13 dic 2020 a las 23:11, Ohaya lawrence (<xunl... at gmail.com>)
escribió:

> Hello everyone, I'm a green hand of CP2K. I try to compare the speed of
> CP2K and Vasp with  Zr(110) optimization. But  I fail to get converge
> for  Zr(110) optimization after 11 hours-running. Here are my input and
> output files.  I want to know why the same system in CP2K is so slow
> (compare with  2 hours-running in Vasp) and how to get a faster calculation
> in CP2K.
>
> --
> You received this message because you are subscribed to the Google Groups
> "cp2k" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to cp... at googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/cp2k/e70f11a7-d228-4bfd-91f1-a9c45c024d0bn%40googlegroups.com
> <https://groups.google.com/d/msgid/cp2k/e70f11a7-d228-4bfd-91f1-a9c45c024d0bn%40googlegroups.com?utm_medium=email&utm_source=footer>
> .
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20201214/8a743456/attachment.htm>