QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: lamkt on April 5, 2010, 10:03

Title: Nedged Elastic Band method
Post by: lamkt on April 5, 2010, 10:03

Hi,

I'm asking regarding the NEB method.  I tried modifying the code from the tutorial to apply the NEB method to a bulk material to understand some phase transition issue.  However, I keep getting force=nan error.  I've narrowed it down to the codes in NEB.py when it tried to get the tangent between images which gives a nan value.  As I'm not sure of how to get the tangent, or what it means, so I don't know how to change to code to make it works.

Any suggestions are greatly appreciated.  Thanks in advance.

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Note: I've modified the code NEB.py and somehow it works.

Change the line:
        utangent=tangent/length(tangent)

To:
        if max(tangent)-0. < 0.01:
          utangent=tangent
        else:
          utangent=tangent/length(tangent)

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