Search found 8 matches

by lexa
Wed Mar 06, 2019 8:54 am
Forum: VTSTTools
Topic: Dimer method vs NEB
Replies: 1
Views: 9864

Dimer method vs NEB

Hi, I am a frequent user of NEB and now I am trying to learn to use the dimer method. I find NEB somewhat intuitive, I will give an example with a simple molecule. If I want to calculate the barrier for hydrogen abstraction from CH4 on a surface, I will relax two endpoints CH3 + H* and do an interpo...
by lexa
Mon Nov 05, 2018 3:41 am
Forum: VTSTTools
Topic: No transition state found
Replies: 1
Views: 9929

No transition state found

Hi, I have relaxed my initial and final state using exactly the same parameters. The final state is about 0.3 eV higher than the initial state. When I run CI-NEB with 9 images (I tired 5 images at first) all I get is an energy profile that increases monotonically between the initial and final states...
by lexa
Tue Jul 25, 2017 1:04 am
Forum: VTSTTools
Topic: Calculating entropy and ZPE before and after adsorption
Replies: 4
Views: 20027

Re: Calculating entropy and ZPE before and after adsorption

Can you please tell me which script is used to obtain the vibrational entropy term? have used dymzpbar.pl to obtain the ZPE and that works.

Thanks
by lexa
Mon Jul 24, 2017 6:14 am
Forum: VTSTTools
Topic: Calculating entropy and ZPE before and after adsorption
Replies: 4
Views: 20027

Calculating entropy and ZPE before and after adsorption

Hi,

I want to calculate the Gibbs free energy of a reaction where a molecule adsorbs to the surface.

I am wondering whether your scripts allows the calculation of the entropy and zero point energies of the adrobate before and after adsorption?

Thanks,
Alexandra
by lexa
Thu Mar 24, 2011 8:17 am
Forum: VTSTTools
Topic: Oxygen interstitial diffusion
Replies: 0
Views: 10300

Oxygen interstitial diffusion

Hi all, I am trying to calculate the diffusion path of Oxygen in Silicon. The literature says that the Oxygen sits in the mid of a Si-Si bond. Before running the NEB i fully relax my system with an Oxygen atom nearly sitting at the mid of a Si-Si bond. I am not able to reproduce the the Si-O-Si conf...
by lexa
Mon Feb 14, 2011 9:29 am
Forum: VTSTTools
Topic: nebmovie.pl
Replies: 4
Views: 10843

Re: nebmovie.pl

Dear Chill and Graeme, I am using the other VTST scripts like nebmake.pl and nebbarrier.pl without any problems and I do have all the scripts in the same directory. Also when I run /usr/bin/env perl -v I get the version details: "This is perl, v5.8.8 built for x86_64-linux-thread-multi" et...
by lexa
Sat Feb 12, 2011 5:49 pm
Forum: VTSTTools
Topic: nebmovie.pl
Replies: 4
Views: 10843

nebmovie.pl

Hi, When I run the nebmovie.pl script I get the following message: Using POSCARs to generate movie sh: /export4/work/ht409/vtst/pos2con.pl: Permission denied sh: /export4/work/ht409/vtst/con2xyz.pl: Permission denied sh: /export4/work/ht409/vtst/pos2con.pl: Permission denied cp: cannot stat `POSCAR_...
by lexa
Fri Feb 11, 2011 6:41 pm
Forum: VTSTTools
Topic: Relax geometries before NEB??
Replies: 1
Views: 5881

Relax geometries before NEB??

Hi,

Sorry for my naive question but I am new to VASP and the NEB method:
Should I relax the initial and final positions then interpolate their resulting CONTCARS using nebmake.pl??

Thanks,
Alexandra