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NEB convergence problem

Posted: Mon Jun 26, 2023 4:51 pm
by alok_shukla1
Dear Experts,
I am facing the convergence issue in one of the NEB calculations for one 2d system. After 132 iterations, I didn't get the convergence, and the run time was over.
Please suggest if any changes I can do to achieve convergence or please suggest if something wrong in my input files.

https://drive.google.com/file/d/1Y4OYhx ... drive_link

Re: NEB convergence problem

Posted: Tue Jun 27, 2023 3:30 pm
by fabien_tran1
Hi,

The problem seems to be due to "POTIM=0" in INCAR; no change in the structure and the forces were never decreasing. At IBRION it is written:
"Mind: For IBRION=3, a reasonable time step must be supplied by the POTIM parameter. Too large time steps will result in divergence, too small ones will slow down the convergence. The stable time step is usually twice the smallest line minimization step in the conjugate gradient algorithm. "

Re: NEB convergence problem

Posted: Tue Jun 27, 2023 3:46 pm
by alok_shukla1
Dear Expert,
Thank you so much for your suggestion. I'll implement your suggestion in the calculation.
I'll update here If I'll get the correct results.