UT theoretical chemistry code forum

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 ...

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 ...

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

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

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 ...

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" etc ...

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 ...

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