NEB: tangent and chain-force are NaN for the last image

[linpo]

I started a NEB job with 4 images. As the job is running, I checked the OUTCAR after 1 ionic step, and found in 04/OUTCAR:

energy of chain is (eV) 0.000000 for this image 0.000000
tangential force (eV/A) NaN
left and right image 0.920129 0.000000 A
TANGENT CHAIN-FORCE (eV/Angst)
-----------------------------------------------------------------------------------
NaN NaN NaN NaN NaN NaN
NaN NaN NaN NaN NaN NaN
......

while for the first 3 images, the output is like
energy of chain is (eV) 0.000000 for this image 0.000000
tangential force (eV/A) 0.183011
left and right image 0.920129 0.920129 A
TANGENT CHAIN-FORCE (eV/Angst)
-----------------------------------------------------------------------------------
0.05618 0.00000 0.48906 -0.010281 0.000000 -0.089503
0.01363 0.00000 0.54320 -0.002494 0.000000 -0.099411
......

Here I list paratmeters that I think is relavent :
IBRION = 1
POTIM = 0.5
IMAGES = 4
SPRING = -5

Any idea about those NAN's? Thanks

[graeme]

Do you have a final state POSCAR file in the 05 subdirectory?

[linpo]

I have one 05/POSCAR.

I have found the problem. I mistakely copied 05/POSCAR to 04/POSCAR. Now it runs well. Thanks for your response.

<span class='smallblacktext'>[ Edited Thu Feb 21 2008, 06:44PM ]</span>