Ignoring ALGO Fast warnings

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jeremiah
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Ignoring ALGO Fast warnings

#1 Post by jeremiah » Fri May 12, 2023 10:36 pm

Hello,

Is it safe to ignore the messages "num prob" and "WARNING in EDDRMM" for ALGO Fast as suggested in this forum post?

forum/viewtopic.php?f=3&t=17822

The answer in that post mentioned commenting out the WRITE statements in rmm-diis.F, but I am still getting the warning in VASP 6.3.2. I am also wondering about the "num prob" messages that are sometimes printed out many times along with the EDDRMM warning.

Thank you,
Jeremiah

marie-therese.huebsch
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Re: Ignoring ALGO Fast warnings

#2 Post by marie-therese.huebsch » Mon Jun 12, 2023 5:53 am

Hi,

Yes, it is safe. The write statements still haven't been removed. That should be done in the future. Sorry, you invested time in searching for the meaning of this warning.

Marie-Therese

jeremiah
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Re: Ignoring ALGO Fast warnings

#3 Post by jeremiah » Wed Jun 28, 2023 8:14 pm

Good to know, thank you.

william_watson
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Re: Ignoring ALGO Fast warnings

#4 Post by william_watson » Sat Jul 22, 2023 10:36 am

Can I ask why it is safe to ignore the 'WARNING in EDDRMM' and 'numprob' errors? Is there a limit at which you cannot ignore these warnings e.g. if you see more than approximately n instances in your output (.o*) file?

marie-therese.huebsch
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Re: Ignoring ALGO Fast warnings

#5 Post by marie-therese.huebsch » Tue Nov 28, 2023 7:54 am

As explained by Jürgen Furthmüller:
It occurs if you are very close to machine
accuracy in the RMM-DIIS scheme and single band iteration only results in "random" progress
anymore (due to machine accuracy limits). It says then indirectly to you "could not optimize
this band further" -- and the internal action taken is then simply NOT to update the wave
function further and to proceed with the next band(s).
So you can always ignore that warning.

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