Convergence problem of SS-NEB

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Convergence problem of SS-NEB

Post by Kieutrang » Tue Sep 03, 2019 2:01 am

Dear Prof. Henkelman and users,

I am simulating the phase transition of MoTe2 from 2H to 1T'. Since the two phases have different unit cells, the SS-NEB is used. But it is difficult
to get atomic forces below a threshold such as 0.05 eV/Ang.

At first, I tried to do a rough calculation with IMAGES=5, EDIFFG=-0.1 and LCINEB=.TRUE.. But atomic forces are still large after 100 steps. Then
I tried to close the CINEB with IMAGSE=5, EDIFFG=-0.1 and LCINEB=.FALSE.. It worked and converged at a proper state. Using the CONTCARs of
the last step as the new POSCARs, I repeated the work with EDIFFG=-0.07 and LCINEB=.FALSE.. Everything was fine. But when I improved the convergence criteria with EDIFFG=-0.05 and LCINEB=.FALSE., it didn't converge again.

Here I attached the files that I used with EDIFFG=-0.05 and LCINEB=.FALSE.. Could you please give me some suggestion or possible solution to my problem? Thanks in advance.

Best regards,

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Re: Convergence problem of SS-NEB

Post by graeme » Tue Sep 03, 2019 12:55 pm

If you post a .tar.gz file of the calculation (without CHG* WAV* files), I can take a look.

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