Search found 1836 matches

by graeme
Sun Jul 14, 2019 6:12 pm
Forum: VTSTTools
Topic: Forces are not minimized even after many steps during CINEB calculation
Replies: 3
Views: 46

Re: Forces are not minimized even after many steps during CINEB calculation

In the attached, I've used some cheaper computational settings, which I recommend for saddle point calculations. I also froze one atom to get rid of zero modes. Then, a conservative optimizer with a sufficient number of images appears to result in a NEB calculation that is systematically converging.
by graeme
Sun Jul 14, 2019 12:53 am
Forum: VTSTTools
Topic: cNEB Diverges in specific images
Replies: 1
Views: 18

Re: cNEB Diverges in specific images

I used less computationally expensive settings and somewhat more conservative optimizer settings to reconverge both the endpoints and the neb. The primary barrier is 0.82 eV, but note that it looks like it will be a two-step process. The high spring constant for the CO2 molecule required a lower tim...
by graeme
Fri Jul 05, 2019 1:57 pm
Forum: VTSTTools
Topic: Can a DynMat calculation for an isolated molecule be done?Can a DynMat calculation for an isolated molecule be done?
Replies: 1
Views: 319

Re: Can a DynMat calculation for an isolated molecule be done?Can a DynMat calculation for an isolated molecule be done?

That is exactly right - but make sure to set NSW to 25. It may still work with a larger value, but I'm not sure.

When you calculate the zero point energy, remember to remove the 6 near-zero modes, corresponding to translation and rotation.
by graeme
Mon Jul 01, 2019 1:29 pm
Forum: Bader
Topic: Charge transfer in solution!!
Replies: 1
Views: 344

Re: Charge transfer in solution!!

Yes, that bader code should work for that.
by graeme
Thu Jun 27, 2019 2:11 pm
Forum: eOn
Topic: how to change the submission script from "qsub" to "slurm (sbatch) queue system
Replies: 10
Views: 13042

Re: how to change the submission script from "qsub" to "slurm (sbatch) queue system

The submit script can remain the same for an NEB calculation; you just need to add the IMAGES tag to your INCAR file.
by graeme
Mon Jun 24, 2019 2:15 pm
Forum: Bader
Topic: More relaxation for Bader charge analysis
Replies: 2
Views: 246

Re: More relaxation for Bader charge analysis

Yes, that works just fine. You can relax a structure, and the charge density files will be printed at the end of the calculation.
by graeme
Mon Jun 17, 2019 1:25 pm
Forum: VTSTTools
Topic: Cl-NEB calculation problem
Replies: 3
Views: 309

Re: Cl-NEB calculation problem

Yes, that is right. The built in NEB calculator in vasp is fine, but it does not have the climbing image or NEB-aware optimizers.
by graeme
Mon Jun 17, 2019 12:45 pm
Forum: VTSTTools
Topic: Cl-NEB calculation problem
Replies: 3
Views: 309

Re: Cl-NEB calculation problem

Most likely, you do not have our vtstcode linked into your vasp binary. You can grep for "VTST" in your OUTCAR to check.
by graeme
Sun Jun 02, 2019 2:43 pm
Forum: VTSTTools
Topic: copyright?
Replies: 1
Views: 236

Re: copyright?

Yes, it is available for commercial use. Anyone can use if for any purpose.
by graeme
Fri May 31, 2019 7:39 pm
Forum: Bader
Topic: AECCAR0 has NaN value
Replies: 3
Views: 426

Re: AECCAR0 has NaN value

I can't; I don't know what is going wrong. This is a problem internal to the vasp code and it needs to be sorted out by the vasp developers.
by graeme
Sat May 25, 2019 1:18 pm
Forum: Bader
Topic: AECCAR0 has NaN value
Replies: 3
Views: 426

Re: AECCAR0 has NaN value

Yes, I have seen problems with AECCAR0 files but I don't know why it happens. This is a question for the vasp guys.
by graeme
Wed May 08, 2019 2:10 am
Forum: VTSTTools
Topic: system very near to the ground state
Replies: 4
Views: 671

Re: system very near to the ground state

Well, I see what you mean. I can reproduce the problem but I'm not sure what's going on.

I'll keep poking at it.
by graeme
Wed May 01, 2019 6:51 pm
Forum: VTSTTools
Topic: system very near to the ground state
Replies: 4
Views: 671

Re: system very near to the ground state

I would have to see more about the calculation to try to understand why the energy is dropping slowly. For example, are there soft modes in the system such as rotations or translations along which the energy changes slowly? Also, seeing the INCAR and OUTCAR would help. If you want to make a tar.gz o...
by graeme
Sun Apr 28, 2019 4:55 pm
Forum: VTSTTools
Topic: During a TS search, freeze the catalyst or not ?
Replies: 2
Views: 492

Re: During a TS search, freeze the catalyst or not ?

It sounds like you know both the initial and final states of your reaction of interest. I suggest using an NEB calculation to find the saddle point that connects them.
by graeme
Wed Apr 10, 2019 12:15 pm
Forum: Bader
Topic: Could a fractional spin number be possible
Replies: 4
Views: 873

Re: Could a fractional spin number be possible

It's true that the total spin will be an integer, but the integrated spin around an atom does not need to be.

This is similar to the charge of an atom. We typically think about formal (integer) charges, but in reality electrons do not completely localize on atoms in the solid state.