UT theoretical chemistry code forum

Dear Prof. Graeme and others,

I would like to find a transition state with structures having different unit cell. I have found that your group published a paper about this one. Is it available in VTST tool?

Thank you for all your help.

With kinds regards,
Dinh Loc Duong

Yes, it is included in the latest vtstcode (3.x).

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

you can turn it on with LNEBCELL=.TRUE.

I got it.

Thank you.

With best wishes,
Loc.

Dear Prof. Graeme,

Is it possible for you to post the input file used in D. Sheppard, P. Xiao, W. Chemelewski, D. D. Johnson, and G. Henkelman A generalized solid-state nudged elastic band method, J. Chem. Phys. 136, 074103 (2012)? This is the best way for us to learn how to use VTST tool for ss-neb.

With best wishes,
Loc.

Very good idea; Penghao will upload an example calculation.

Thank you for your efforts to help us.

With best wishes,
Loc.

Here we go. See the attachment for the example of the CdSe wurtzite to rock salt transition in a unit cell.

SSNEB is also available in TSASE, which is more handy: http://theory.cm.utexas.edu/henkelman/code/tsase.php
An example folder can be found when checked out.

HI PengHao,

Thank you for your upload file.

With best wishes,
Loc.

Dear Prof. Graeme and Mr. Penghao,

I am running the example files given by Mr. Penghao without changing anything, but the SSNEB doesn't seem to converge i.e. maximum step (10) reached. Also, when I made the intermediate images from nebmake.pl using geometry from the 00 and 06 directory, they POSCAR files are different from POSCAR in the example. Did I do something wrong?

PS. Version of our VASP is 5.4.1, is it not compatible with the current vtst ?

I would not expect to converge a pathway in 10 steps. This calculation is just like any optimization; check that the forces are dropping steadily and continue until convergence is reached. If something is preventing convergence, in the sense that the forces are not dropping, we can take a look at the calculation files (input and output) to see what's going wrong.

Dear Prof. Graeme,

I give the input and output. "Original.tar.gz" contains the original input file by mr. Penghao, "nsw100.tar.gz" contains the original input file with the modified NSW to 100 which does not converge either. Any helps are greatly appreciated

You do not appear to have our vtstcode linked into your vasp binary.

To do this, see these instructions: http://theory.cm.utexas.edu/vtsttools/installation.html

Oh, that is the issue, thanks.