Search found 8 matches

by Soon Ho Kwon
Fri Jan 24, 2020 4:15 am
Forum: VTSTTools
Topic: H2O drifting away during NEB
Replies: 6
Views: 9365

Re: H2O drifting away during NEB

Dear, prof. Graeme.

Your results obviously show that it's not a problem of the pathway but the optimizer I used. I might need to use QM (or FIRE) and test those variables.

Thank you so much for your help.
Have a wonderful day & weekend!

Sincerely,
Soonho
by Soon Ho Kwon
Wed Jan 22, 2020 4:50 pm
Forum: VTSTTools
Topic: H2O drifting away during NEB
Replies: 6
Views: 9365

Re: H2O drifting away during NEB

First of all, Thank you for your help. I noticed that you relaxed the structure at the neutral net charge of the system for the initial state. Since I tried to mimic the large negative potential environment, I increased the total number of electron on purpose which evokes water desorption and makes ...
by Soon Ho Kwon
Wed Jan 15, 2020 6:53 pm
Forum: VTSTTools
Topic: H2O drifting away during NEB
Replies: 6
Views: 9365

Re: H2O drifting away during NEB

Thank you so much for your prompt response.
I'm also trying to see if # of images (to reduce the distance below 1 A) or LBFGS optimizer can resolve this problem.

I hope you have a lovely day!

Sincerely,
Soonho
by Soon Ho Kwon
Wed Jan 15, 2020 2:35 am
Forum: VTSTTools
Topic: H2O drifting away during NEB
Replies: 6
Views: 9365

H2O drifting away during NEB

Hello, prof. Graeme I'm struggling with proton transfer from neutral water to Cu(111). (Volmer reaction) I have 3 H2O in the system and the final state would be 2H2O(l)+OH*+H*. During the NEB, H2O drift away from the surface making high forces as follows. Step max_force barrier image delta_barrier 0...
by Soon Ho Kwon
Fri Apr 24, 2015 5:30 am
Forum: VTSTTools
Topic: [NEB] Energy barrier depends on number of images
Replies: 9
Views: 15947

Re: [NEB] Energy barrier depends on number of images

[quote="graeme"]Oh I see. You should use the climbing image method so that a single image will converge right to the saddle.[/quote] Dear Dr. Henkelman, Thanks for your response, again. The thing is that I already used the climbing image method as you can see the OUTCAR file. OPT: Using VA...
by Soon Ho Kwon
Thu Apr 23, 2015 6:27 am
Forum: VTSTTools
Topic: [NEB] Energy barrier depends on number of images
Replies: 9
Views: 15947

Re: [NEB] Energy barrier depends on number of images

[quote="graeme"]I'm looking at the energy pathway that you posted. You may view this as a single mechanism, but there is clearly an intermediate minimum along the path. I suggest minimizing that image (the 5th point in your plot) to see what minimum that corresponds to. Then, calculate sep...
by Soon Ho Kwon
Wed Apr 22, 2015 6:00 am
Forum: VTSTTools
Topic: [NEB] Energy barrier depends on number of images
Replies: 9
Views: 15947

Re: [NEB] Energy barrier depends on number of images

[quote="graeme"]I suggest minimizing the intermediate configuration and run two separate bands of 3-5 images for each elementary step.[/quote] Thanks for the quick reply. But did you understood that the attached figure (and my question) is about energy barrier vs. reaction coordinate? Actu...
by Soon Ho Kwon
Tue Apr 21, 2015 4:37 am
Forum: VTSTTools
Topic: [NEB] Energy barrier depends on number of images
Replies: 9
Views: 15947

[NEB] Energy barrier depends on number of images

Hi. I'm calculating the energy barrier of CO oxidation. Although I found some posts about the appropriate number of images (3~5 or 4, 6, 8), I have a question. My calculation shows that the energy barrier depends on the number of images. (I attached a graph about it) I'm wondering that 4 images are ...