improved dimer method paramters tuning

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sxd375
Posts: 3
Joined: Tue Feb 13, 2018 3:30 pm

improved dimer method paramters tuning

Post by sxd375 » Tue Feb 13, 2018 3:55 pm

I have been running the TS state using improved dimer method since cl-NEB failed to converge to the Force criterion -0.05 ev on just one or two atoms, though they came out close to -0.06 ev on these but did not go down further. Hence I did vibration calculation on highest image before using the improved dimer method. However, after just a few runs the forces went even higher to -0.1 ev on these atoms(the curvature was negative though)
The INCAR parameters for DIMER are the default that I am using


# DIMER PARAMETERS
FINDIFF = 2
DIMER_DIST=0.01
MINROT=0.01
STEP_SIZE=0.01
STEP_MAX=0.1

since Forces to go down are quite close to the given criteria, I guess I need to know what parameters in the above can be tuned to very low values so that the structure remained close to the one I gave in the start and it only adjusts the atoms on which the forces are not within the criteria. Please let me know.
Thanks

graeme
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Re: improved dimer method paramters tuning

Post by graeme » Tue Feb 13, 2018 4:23 pm

If you can post both the neb and dimer calculation, I can take a look.

sxd375
Posts: 3
Joined: Tue Feb 13, 2018 3:30 pm

Re: improved dimer method paramters tuning

Post by sxd375 » Tue Feb 13, 2018 4:41 pm

Please find here attached the files for Dimer run and NEB calculation with IBRION 1( which I am running with POTIM 0.5, though I tried with very low POTIM like 0.1, 0.2 or other optimiser also). The Dimer calculation has been done on the Highest image 03 of the NEB which will be close in structure to the dimer POSCAR here since I could not find the NEB_run from where I took the dimer starting geometry.

Please let me know.
Thanks
Attachments
dimer.rar
(18.34 MiB) Downloaded 3 times

sxd375
Posts: 3
Joined: Tue Feb 13, 2018 3:30 pm

Re: improved dimer method paramters tuning

Post by sxd375 » Tue Feb 13, 2018 4:45 pm

I tried attaching this file though it didnot show up. so here is the file for NEB.
Attachments
NEB.rar
(39.84 MiB) Downloaded 3 times

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