NEB Help

Vasp transition state theory tools

Moderator: moderators

Post Reply
Manzoor
Posts: 5
Joined: Sat Mar 14, 2015 6:03 am

NEB Help

Post by Manzoor »

I am new VASP and i am trying to find the minimum energy pathway for CO oxidation on Au8 cluster using NEB. I am using the INCAR given below. I have some questions and confusions which i am putting as under.

1) Whether my INCAR tags are appropriate for the calculation
2) How to know which image is an intermediate or a transition state (e.g in g09 we can know this with the help of a negative frequency)
3) I tried to visualize the movie generated after running the nebmovie.pl script using the VMD, molden, avogadro,etc. However i was not able to open it. Can anyone suggest an appropriate visualization software.
Also attached find my NEB calculations.

ISMEAR = 0
SIGMA = 0.05

SPRING = -5
IMAGES = 4
ICHAIN = 0
LCLIMB = .TRUE.

EDIFF = 0.000001
EDIFFG = -0.0005

IBRION = 1
NFREE = 2
NSW = 400

POTIM = 0.01
PREC = High

IALGO = 48
LDIAG = .TRUE.
LSCALAPACK = .FALSE.


#--------------- save memory--------------

ISYM = 0
LCHARG = .FALSE.
LELF = .FALSE.
"INCAR.neb" 38L, 584C

Thanking in advance,
Manzoor.
Manzoor
Posts: 5
Joined: Sat Mar 14, 2015 6:03 am

Re: NEB Help

Post by Manzoor »

I am attaching the NEB.tar file here which contains my calculations

Manzoor
Attachments
NEB.tar
(36.08 MiB) Downloaded 1153 times
graeme
Site Admin
Posts: 2280
Joined: Tue Apr 26, 2005 4:25 am
Contact:

Re: NEB Help

Post by graeme »

The calculation looks reasonable. Two comments:

1. You are not using the vtstcode so the LCLIMB tag will not have any effect. So while the 03 image is currently the highest energy, it will not converge exactly to the saddle (without the vtstcode).

2. You are free to run a dynamical matrix calculation on your saddle point, after doing a climbing image NEB calculation, to verify that it is a first-order saddle.
Manzoor
Posts: 5
Joined: Sat Mar 14, 2015 6:03 am

Re: NEB Help

Post by Manzoor »

Dear Graeme,

Thanks for your reply. May please know how to perform the calculation using the vtstcode and how to run a dynamical matrix calculation.

Thanks and Regards,
Manzoor
graeme
Site Admin
Posts: 2280
Joined: Tue Apr 26, 2005 4:25 am
Contact:

Re: NEB Help

Post by graeme »

Please start by looking at our documentation:

http://theory.cm.utexas.edu/vtsttools/

which contains information about compiling vasp with the vtsttools as well as setting up climbing image and dynamical matrix calculations.
Post Reply