CI-NEB shows lower energy for the images than fixed images

Vasp transition state theory tools

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sapper1
Posts: 19
Joined: Fri Dec 21, 2012 7:37 pm

CI-NEB shows lower energy for the images than fixed images

Post by sapper1 »

Dear Admin, Proff. Graeme,
I am having very weird problem. My couple of images close to initial and final images show lower energy than the initial images. I tried minimizing those low energy images (CONTCAR) but they go back (very close) to initial and final energy. so, I don't thing those images are in global minima. I followed the CI-NEB steps as you suggested before. initial run with IBRION 3, POTIM 0.01, EDIFFG = -0.1, ISYSM = 0 and then I used IOPT 7 with POTIM 0, EDIFFG -0.03 and IBRION 3 as mentioned in the website. I also put ISYM = 0 for all CINEB runs. CINEB also reaches to required accuracy. I have listed the energy of many repeated runs.
thank you very much
best
Hom

Rxn-cord run-1 run-2 run-3 run-4 run-5
0 -286.74457 -286.74457 -286.74457 -286.74457 -286.74457
1 -287.38759 -287.40687 -287.40725 -287.38982 -287.39033
2 -287.30903 -287.35791 -287.36269 -287.35288 -287.34773
3 -286.80049 -287.01569 -287.04532 -287.13975 -287.04853
4 -286.18302 -286.27159 -286.27678 -286.45376 -286.28527
5 -285.89846 -285.93511 -285.93794 -285.9338 -285.91823
6 -286.51636 -286.83192 -286.80442 -286.6573 -286.77961
7 -287.19867 -287.39988 -287.39418 -287.33355 -287.35608
8 -287.50906 -287.61911 -287.61904 -287.57273 -287.57747
9 -287.61637 -287.64392 -287.644 -287.60012 -287.60079
10 -286.93501 -286.93501 -286.93501 -286.93501 -286.93501
here is my INCAR

Startparameter for this Run:
ENCUT = 400
LCHARG = .TRUE.
LWAVE = .TRUE.
ALGO = Fast
ISPIN = 1
ISTART = 1
LREAL = Auto
IDIPOL = 3
IMAGES = 9
SPRING = -5
Electronic Relaxation 1
EDIFF = 1E-05 :stopping-criterion for ELM
EDIFFG = -0.03
Ionic Relaxation
NSW = 300
IBRION = 3 :ionic relax: 0-MD 1-quasi-New 2-CG
ISIF = 2 :stress and relaxation
POTIM = 0
IOPT = 7
LCLIMB = .TRUE.
ISYM=0
NPAR = 4
sapper1
Posts: 19
Joined: Fri Dec 21, 2012 7:37 pm

Re: CI-NEB shows lower energy for the images than fixed imag

Post by sapper1 »

Dear Admin, Proff. Graeme,
here are the initial POSCARS and final CONTCARS and OUTCARS
thank you
best
Hom
Attachments
OUTPUT.7z
Output
(1.17 MiB) Downloaded 781 times
inputs.zip
input files
(14.46 KiB) Downloaded 788 times
sapper1
Posts: 19
Joined: Fri Dec 21, 2012 7:37 pm

Re: CI-NEB shows lower energy for the images than fixed imag

Post by sapper1 »

OUTCARS from the last run
thanks
Attachments
1-4 outcars.zip
(1.2 MiB) Downloaded 812 times
sapper1
Posts: 19
Joined: Fri Dec 21, 2012 7:37 pm

Re: CI-NEB shows lower energy for the images than fixed imag

Post by sapper1 »

remaining
Attachments
5-9 outcars.zip
(1.35 MiB) Downloaded 779 times
graeme
Site Admin
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Joined: Tue Apr 26, 2005 4:25 am
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Re: CI-NEB shows lower energy for the images than fixed imag

Post by graeme »

I don't see the OUTCARs for the 00 and 10 (reactant and product directories), but the NEB looks just fine. The force on the climbing image (05) is low (<0.01 eV/Ang). Without the endpoint OUTCAR files, I can't address the problem of images having a lower energy, but again, I don't see anything wrong with the NEB.
sapper1
Posts: 19
Joined: Fri Dec 21, 2012 7:37 pm

Re: CI-NEB shows lower energy for the images than fixed imag

Post by sapper1 »

Thank you very much Proff. Graeme for the quick reply . here is the OUTCAR-00 and OUTCAR-10
thanks
best
Hom
Attachments
OUTCAR-10.7z
(172.87 KiB) Downloaded 766 times
OUTCAR-00.7z
(173.92 KiB) Downloaded 782 times
graeme
Site Admin
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Joined: Tue Apr 26, 2005 4:25 am
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Re: CI-NEB shows lower energy for the images than fixed imag

Post by graeme »

You have a different k-point mesh for the 00 and 10 images. Use ISYM=0 for the endpoint calculations as well.
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