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NEB energy oscillating

Posted: Mon Aug 27, 2018 2:01 am
by sinfire
Hi all,

I'm doing a NEB calculation on oxygen dissociation.

As I checked the energies, it seems to be oscillating(or 'stuck' I'd say).

(The cnvg-f.txt file in the attachment is the result from
grep "F=" stdout
to look at E and dE)

Is this or common thing or should I rerun the calculation with different settings (like more finer EDIFF)?

Is there anything I can do other than waiting till the calculation converges?

For the note, I'm also doing a run with

IOPT=7
TIMESTEP = 0.01

but that job also seems to be oscillating.

Thanks in advance.

(I only included CONTCAR, OUTCAR, POSCARs in the attachment due to size issues)

Re: NEB energy oscillating

Posted: Mon Aug 27, 2018 2:25 am
by graeme
You don't have our VTST code linked into your vasp binary.

Re: NEB energy oscillating

Posted: Mon Aug 27, 2018 10:27 am
by sinfire
Thank you for the reply.

I noticed there's another executable and now it seems to be working.

======================================
...
VTST: version 3.1, (03/28/14)

CHAIN: initializing optimizer

OPT: Using VASP QUASI-newton optimizer
CHAIN: Read ICHAIN 0
CHAIN: Running the NEB
NEB: SPRING -5.000000
NEB: LCLIMB T
NEB: LTANGENTOLD F
NEB: LDNEB F
NEB: LDNEBORG F
NEB: LNEBCELL F
NEB: EFIRST 0.000000
NEB: ELAST 0.000000
....
========================================

I'd like to add another stupid question, so for my previous run,
VASP was running the NEB ignoring the LCLIMB option and using the old NEB method implemented in VASP, correct?

Re: NEB energy oscillating

Posted: Mon Aug 27, 2018 12:10 pm
by graeme
yes, that's right.