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Optimizer IOPT=2

Posted: Wed Apr 05, 2023 9:17 am
by Ammi
Hello,

Is it possible to run neb directly with the optimizer IOPT=2 even if there are high forces at some images where with nebmake.pl a short distance of about 1.2 Ang between two atoms can be found?

Thanks

Re: Optimizer IOPT=2

Posted: Wed Apr 05, 2023 2:09 pm
by graeme
Yes, but you may need to set MaxMove to a smallish value to keep the initial steps in the optimization stable.

But better would be to use the nebmake.py script, which will apply the IDPP method and try to keep the bond lengths more constant in your initial band.

Re: Optimizer IOPT=2

Posted: Wed Apr 05, 2023 7:52 pm
by Ammi
Thanks.

How can we use nebmake.py, there is no information in the online manual? Should we use after nebmake.pl?

Re: Optimizer IOPT=2

Posted: Wed Apr 05, 2023 9:13 pm
by graeme
no, just run nebmake.py in the same way that you would nebmake.pl - it will apply the IDPP

Re: Optimizer IOPT=2

Posted: Thu Apr 06, 2023 8:37 am
by Ammi
OK thanks.

Yes, it gives images with reasonable bond distances.
So, now I will try IOPT=2 with its default settings and see.