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I want to learn how to specify the "relaxation of atoms perpendicular to the reaction path" in NEB calculation?

Is it different from a normal relaxation process? Which parameter should i write into the INCAR file and what is its default value during NEB?

What happened to reading manuals or websites first?

I created all inter geometries between initial and final states. I prepared an INCAR file according to the manuel and put the NSW =1. because in my opininon i dont need any relaxation at this stage, because i have the stable geometry. but in a few paper, i saw some explanations about perpendicular forces during NEB. Actually, i dont understand the logic of perpendicular relaxation to the reaction path. can you tell me its meaning please?

thank you much.

Hi

In NEB calculations, you cannot allow a complete relaxation of all forces. If you do so, the transition state will likely get back to a more stable state.

This is the reason why the NEB calculation only optimizes some components of the forces.

But you don't have to care about this, you just perform your NEB calculation and it will take care of this for you.

Regards

Dear Boris
Thank you for your attention.

But my problem still continues. An example of a sentence from a paper "In the first levels, typically more than 100 iterations of NEB were carried out until the forces perpendicular to the reaction path were considerably small." or another says " The NEB method takes a set of images of the system between the initial and final states and optimizes them simultaneously in a subspaceperpendicular to the imaginary line connecting the images."

Here i dont understand this. if the NEB calculation does a relaxation, the geometry goes its most stable structure. so what does those sentences above tell us?