Search found 2118 matches

by graeme
Tue Aug 02, 2022 3:57 pm
Forum: eOn
Topic: Question about EON and vasp
Replies: 3
Views: 110

Re: Question about EON and vasp

I am very interested in getting to the bottom of this, but I'm not able to debug it with the output information. I see a number of worrisome things, but I'm thinking that it may be due to (i) the python environment and (ii) the mpi+vasp setup. I'm going to write you separately and include a student ...
by graeme
Mon Aug 01, 2022 1:04 pm
Forum: VTSTTools
Topic: Problem compiling instanton.F
Replies: 6
Views: 5579

Re: Problem compiling instanton.F

If you are just trying to compile the vtstcode into your version of vasp, you do not need a patch. Instead, you just need to copy the vtstcode files into your vasp source directory and then modify the .objects file as described here: https://theory.cm.utexas.edu/vtsttools/installation.html If you ar...
by graeme
Sun Jul 31, 2022 12:25 am
Forum: VTSTTools
Topic: NEB Convergence problem
Replies: 3
Views: 129

Re: NEB Convergence problem

Ok, it sounds like you have what you need to make things work. Great!
by graeme
Thu Jul 28, 2022 11:20 pm
Forum: VTSTTools
Topic: Convergence issue with cation migration in bulk tio2
Replies: 9
Views: 197

Re: Convergence issue with cation migration in bulk tio2

No, it really depends upon the path, and in particularly how linear it is or how close your initial path is. I have seen calculations of hundreds of paths and some range of simple one which converge in a few iterations with one image, and ones that require 10-00 images and many more iterations with ...
by graeme
Thu Jul 28, 2022 3:17 pm
Forum: VTSTTools
Topic: Convergence issue with cation migration in bulk tio2
Replies: 9
Views: 197

Re: Convergence issue with cation migration in bulk tio2

I think there may be a misunderstanding about convergence. Take, for example, your 331/CINEB_NO_FIX/LOW , you can see a single barrier around 4.9 eV. It is true that this is not converged in the sense that the forces are around 0.4 eV/Ang and you have requested maximum forces of 0.05 eV/Ang. But tha...
by graeme
Wed Jul 27, 2022 1:41 pm
Forum: VTSTTools
Topic: NEB Convergence problem
Replies: 3
Views: 129

Re: NEB Convergence problem

This calculation look reasonable. The only issue I see is very high forces at the start of the calculation. Switch to a TIMESTEP of 0.01 and run about 20 iterations and make sure that the forces systematically drop from ~30 eV/Ang to <1 eV/Ang. Once all the forces are below 1 eV/Ang, you can go back...
by graeme
Tue Jul 26, 2022 12:13 pm
Forum: VTSTTools
Topic: Transition state calculation stop with high force using DIMER methods and IOPT=1
Replies: 11
Views: 292

Re: Transition state calculation stop with high force using DIMER methods and IOPT=1

Ah, I see. Yes, this is typical and expected behavior. It is just not worth fully converging the dimer rotation at each translation step, only to then translate the dimer and have to rotate it again. Instead, it is better to simultaneously be converging the rotation and translation, especially if yo...
by graeme
Mon Jul 25, 2022 3:18 pm
Forum: VTSTTools
Topic: Convergence issue with cation migration in bulk tio2
Replies: 9
Views: 197

Re: Convergence issue with cation migration in bulk tio2

Oh goodness, you shouldn't lose sleep over the calculation of vacancy diffusion! This is not a difficult calculation - it is just a matter of making a few adjustments. First, you can check if the vtstcode is linked in by greping for VTST in any OUTCAR file and look for a line such as: "VTST: ve...
by graeme
Mon Jul 25, 2022 2:06 pm
Forum: VTSTTools
Topic: Convergence issue with cation migration in bulk tio2
Replies: 9
Views: 197

Re: Convergence issue with cation migration in bulk tio2

These calculations are generally looking ok. I have just a few suggestions: 1. relax the cell without a vacancy (ISIF=3) and then leave the cell fixed for your IS and FS optimizations (ISIF=2) so that the cell does not change over the NEB. 2. I see a small shift in the structures, which is not reall...
by graeme
Sun Jul 24, 2022 2:04 pm
Forum: VTSTTools
Topic: Transition state calculation stop with high force using DIMER methods and IOPT=1
Replies: 11
Views: 292

Re: Transition state calculation stop with high force using DIMER methods and IOPT=1

Ok, I am much happier after seeing your calculation files. First, both IOPT=1 and IOPT=2 converge immediately after 1 iteration. The difference between the force in the DIMCAR and the OUTCAR is due to the fact that the DIMCAR includes a force projection. In both cases the true forces are the same: F...
by graeme
Sun Jul 24, 2022 12:53 pm
Forum: eOn
Topic: EON-mpi Error
Replies: 1
Views: 72

Re: EON-mpi Error

Often I can recognize error messages and provide advise but in this case, I really don't know what is going wrong. It looks like one of the mpi ranks can not read the job files, but I'm not sure why that would be. If you learn more, I might be able to help. Another option, if you want to post the en...
by graeme
Sun Jul 24, 2022 12:39 pm
Forum: eOn
Topic: how to prepare pos.con file?
Replies: 2
Views: 64

Re: how to prepare pos.con file?

The .con format is a bit of a strange and poorly defined format. My suggestion is to make a POSCAR file and then convert it to .con with the vasp2con.pl script in the vtstscripts: https://theory.cm.utexas.edu/vtsttools/scripts.html I can also briefly explain the con format here: Generated by ASE (co...
by graeme
Tue Jul 19, 2022 8:17 pm
Forum: VTSTTools
Topic: Transition state calculation stop with high force using DIMER methods and IOPT=1
Replies: 11
Views: 292

Re: Transition state calculation stop with high force using DIMER methods and IOPT=1

Can you send me a tar file of the two calculations? I really don't understand why the IOPT=1 is terminating when the IOPT=2 is not, and why there is termination when the force is larger than EDIFFG.
by graeme
Mon Jul 18, 2022 8:12 pm
Forum: VTSTTools
Topic: Transition state calculation stop with high force using DIMER methods and IOPT=1
Replies: 11
Views: 292

Re: Transition state calculation stop with high force using DIMER methods and IOPT=1

It looks like the IOPT=1 calculation converged; I don't see any evidence of high forces. Note that just because the IOPT=1 calculation converged after 1 step, this is really just because the force is sufficiently low from the CI-NEB calculation. The geometry did not change in this calculation - it j...
by graeme
Thu Jul 14, 2022 7:27 pm
Forum: VTSTTools
Topic: NEB converge problem with different number of images
Replies: 15
Views: 1043

Re: NEB converge problem with different number of images

It's better; only the force on the free atoms matter.