NEB calculation

[Reetu]

Hi,

I would like to run transition state calculations by using NEB method in vasp 5.4.4. I am totally new to this. I would be highly grateful if somebody can guide me in this. I have optimized the initial and final relaxed structure. But, I am confused about the next step as I have no idea how to compile the vasp according to the script.

Best regards
Reetu

[as68397]

Hello,
You shouldn't have to compile vasp according to the vtstscripts. You will just want to ideally make a new directory, and move your INCAR,KPOINTS,POTCAR, inital_structure_POSCAR, and final_structure_POSCAR into it.
Then edit your INCAR to have the NEB flags you wish to use, the complete list is here: http://theory.cm.utexas.edu/vtsttools/neb.html ,right above References.
Then, If you checkout a copy of vtst, you should be able to just run nebmake.pl initial_strucuture final_structure number_of_images(an int).
eg. $ path_to_vtst_scripts/nebmake.pl POSCAR_REACTANT POSCAR_PRODUCT 5
in this case, it should create 7 files labeled from 00 01 ... 06, where 00 and 06 have the reactant and product POSCARs respectively, and 01 ...05 would be your interpolated images.
Make sure the number of images you make from nebmake.pl matches with the IMAGES flag in the INCAR. Then you should just be able to submit it like any vasp job.
You should also checkout all our neb setup and analysis scripts from here: http://theory.cm.utexas.edu/vtsttools/scripts.html

Feel very free to ask more questions,

Thanks,

Akksay

[graeme]

Just one note; if you want to use the climbing image or our optimizers, you will need to link in our vtstcode into your vasp binary. Instructions for doing that are here: https://theory.cm.utexas.edu/vtsttools/ ... ation.html

[rachita_panigrahi]

hello sir,
i calculated Neb , while i was calculating Neb through vtstscripts nebresults.pl i am getting neb.dat file. i m pasting the neb.dat file here
0.000000 0.000000 6.254298 0
1 3.800600 0.000000 6.254298 1
2 7.823301 -7.357561 3.198173 2
3 12.133317 -11.977086 2.804412 3
4 16.655444 -13.753760 1.125051 4
5 21.341962 -15.338343 0.479410 5
6 26.035792 -14.218954 -3.131456 6
7 30.688084 0.589972 -6.767132 7
8 35.083499 35.590139 -17.821420 8
9 35.548576 35.590139 -17.821420 9
i have one question the 2nd column is the reaction coordinate but my case its showing up to 35.5 armstrong it possible?

[graeme]

There is something very wrong with this calculation. If you post it, I can take a look.

[rachita_panigrahi]

here i attach my INCAR file

ISTART = 0
ISYM = 0
ENCUT = 520
IALGO = 38
EDIFF = 0.0001
NELMIN = 5
NELM = 40
EDIFFG = -0.01
NSW = 200
IMAGES = 8
ISMEAR = 0
SIGMA = 0.05
SPRING = -5
ICHAIN = 0
IOPT = 3
ISIF = 3
LCLIMB = TRUE
LTANGENTOLD = FALSE
LDNEB = FALSE
LNEBCELL = TRUE
LREAL = AUTO
LCHARG = FALSE
LWAVE = FALSE
PREC = NORMAL
IBRION = 3
POTIM = 0
LSCALPACK = FALSE

[graeme]

Please post a .tar.gz file of the calculation. If you remove the CHG* and WAV* it should be a manageable size.

[rachita_panigrahi]

i am sending another NEB file with tar.gz. please suggest me what did i make wrong.

[rachita_panigrahi]

i attach my tar.gz file

[graeme]

Your Na atoms need to be put in the same order in your initial and final states. In the calculation that you posted, the ordering is different and so Na atoms are having to swap positions in the NEB.

[rachita_panigrahi]

thank you so much sir.