Search found 39 matches

by xph
Wed May 02, 2012 4:43 pm
Forum: VTSTTools
Topic: NEB with ISIF=3,4 etc
Replies: 23
Views: 29339

Re: NEB with ISIF=3,4 etc

Sorry, I thought what you posted were neb.dat from nebbarrier.pl
by xph
Wed May 02, 2012 12:38 am
Forum: VTSTTools
Topic: NEB with ISIF=3,4 etc
Replies: 23
Views: 29339

Re: NEB with ISIF=3,4 etc

I think "FMAGFLAG=T" just means converging based on magnitude of the total force rather than converging based on the max atom force. IALGO sets the algorithm used for electronic step. As long as the electronic step converges within NELM, IALGO will not affect the ionic steps. But if something is wro...
by xph
Tue May 01, 2012 2:53 am
Forum: VTSTTools
Topic: NEB with ISIF=3,4 etc
Replies: 23
Views: 29339

Re: NEB with ISIF=3,4 etc

Maybe try to add ICHAIN=0
by xph
Tue May 01, 2012 1:03 am
Forum: VTSTTools
Topic: NEB with ISIF=3,4 etc
Replies: 23
Views: 29339

Re: NEB with ISIF=3,4 etc

Has the VTSTCODE been updated and complied in the last one month?
by xph
Mon Apr 30, 2012 8:08 pm
Forum: VTSTTools
Topic: NEB with ISIF=3,4 etc
Replies: 23
Views: 29339

Re: NEB with ISIF=3,4 etc

Is the OUTCAR in each image folder finished?
by xph
Sun Apr 29, 2012 9:44 pm
Forum: VTSTTools
Topic: NEB with ISIF=3,4 etc
Replies: 23
Views: 29339

Re: NEB with ISIF=3,4 etc

Those should be the velocities of the atoms. It doesn't matter in SSNEB calculation. There is no surprise that the converged structures are similar to the linear interpolated ones, since only two atoms are included in the supercell. I think the barrier should be lower than the initial guess. You can...
by xph
Fri Apr 27, 2012 8:51 pm
Forum: VTSTTools
Topic: NEB with ISIF=3,4 etc
Replies: 23
Views: 29339

Re: NEB with ISIF=3,4 etc

Seems like that you missed POTIM = 0.0
But I am not sure whether the error come from this. Also try to set a larger ENCUT (1.3*ENMAX).
by xph
Fri Apr 27, 2012 6:06 am
Forum: VTSTTools
Topic: NEB with ISIF=3,4 etc
Replies: 23
Views: 29339

Re: NEB with ISIF=3,4 etc

Can you post your INCAR so that we can look into it ?
by xph
Mon Apr 23, 2012 3:07 am
Forum: VTSTTools
Topic: NEB with ISIF=3,4 etc
Replies: 23
Views: 29339

Re: NEB with ISIF=3,4 etc

Yes, the default is PSTRESS = 0, in the unit of 0.1GPa (kB) . It is not necessary to set PSTRESS.
by xph
Wed Apr 18, 2012 11:11 pm
Forum: VTSTTools
Topic: NEB with ISIF=3,4 etc
Replies: 23
Views: 29339

Re: NEB with ISIF=3,4 etc

You may need to update to the latest version of VTSTCODE.

LNEBCELL is the flag to turn on solid state NEB, which includes the cell variables in the reaction coordinates.
The paper on the SSNEB method can be found here:
http://theory.cm.utexas.edu/henkelman/p ... 074103.pdf
by xph
Wed Apr 18, 2012 6:34 pm
Forum: VTSTTools
Topic: NEB with ISIF=3,4 etc
Replies: 23
Views: 29339

Re: NEB with ISIF=3,4 etc

Yes, you can use the solid state NEB by setting LNEBCELL = True, ISIF=3, and IOPT =3
There are details discussed here:
viewtopic.php?f=2&t=1136
by xph
Sun Apr 08, 2012 4:49 am
Forum: VTSTTools
Topic: how to acquire accurate POSCAR in saddle point from CL_NEB?
Replies: 4
Views: 6524

Re: how to acquire accurate POSCAR in saddle point from CL_N

The spline mep curve can be misleading sometimes. As long as the forces converged (usually 0.01 is enough), the climbing image is at the saddle point. The higher energy section on mep.eps is just the fault of spline.
by xph
Fri Apr 06, 2012 6:53 pm
Forum: VTSTTools
Topic: how to acquire accurate POSCAR in saddle point from CL_NEB?
Replies: 4
Views: 6524

Re: how to acquire accurate POSCAR in saddle point from CL_N

You can get the climbing image number from neb.dat. The CONTCAR file in the folder with the name of that number is what you want.
As along as the EDIFFG is small enough, this saddle point structure is accurate. Do not optimize when you calculate the frequency.
by xph
Mon Apr 02, 2012 5:06 pm
Forum: VTSTTools
Topic: solid state CI-NEB, not converge
Replies: 34
Views: 35171

Re: solid state CI-NEB, not converge

Yes, it is enthalpy in TSASE. I just compared the results between TSASE and VTST. Replacing the energies in nebss.dat with enthalpies from TSASE smoothes the path. I think this will solve your problem. You can do it by hand if your are in hurry. Just read enthalpy of each image from OSZICAR and divi...