How can I determine the reaction barrier after a NEB calculation.

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pqyuan · #1 Post by **pqyuan** » Sun Jun 04, 2006 3:27 am

hi,
I have performed a NEB calculation with 4 images, and it converged after several days' calculation. But I don't know how to get the barrier from the obtained 4 OURCARs. Can anyone be kindly to give me some hint?

job · #2 Post by **job** » Wed Jun 07, 2006 10:29 am

Plot total energy vs. NEB image number? max-min == barrier (depending on which way you want to go).

tjf · #3 Post by **tjf** » Wed Jun 07, 2006 2:27 pm

[quote="= barrier (depending on which way you want to go).[/quote"]

I'm sure you meant to say max-min == really bad approximation to barrier, right? ;-)

With just four images you're not going to be very close (depending, as always, on the system). You will get a lower bound for the barrier, though.

#4 Post by **admin** » Tue Jun 13, 2006 8:09 am

depending on the reaction path, I also suggest to do an additional NEB run between the two images which are adjacent to the
transition state to get a refined barrier height.