UT theoretical chemistry code forum

Dear prof. Henkelman,

I used CI-NEB to find the diffusion path with 5 images, in one calculation after convergence to <0.01 eV/Ang:

from neb.dat, the transition state is at image3:

0 0.000000 0.000000 0.000000 0
1 0.684453 0.240176 -0.443828 1
2 1.367635 0.405261 -0.069436 2
3 2.048908 0 ...

Dear Prof. Henkelman,

I used CI-NEB to find the mep for Li ion migration in a large bulk supercell.

I have checked the forum and found that to perform subsequent phonon frequency calculations, but such large bulk supercell has too many degrees of freedom.

Is it necessary to check all degrees of ...

Thank you very much prof. Henkelman

Dear Prof. Henkelman,

I have used the relaxed files of 01-opt and 05-opt and rerun the NEB calculation.

The mep figure and spline file are attached. Is it reasonable?
If it is OK, I will rerun the calculation with the aggressive parameters.

Best regards,
Ibrahim

Thanks Prof. Henkelman,

Could I continue with that NEB calculation and consider the barrier relative to those minimum images?
Or should I use those images as endpoints then construct again 5 images and do neb calculation?

I am calculating the migration barrier by removing only one atom from the ...

Yes they give minimum energy than endpoints and do not relax back to the endpoints.

Yes I tried and used ISYM=0 for images and endpoints with the same results

Dear Prof. Henkelman,

So no problem in neb1?

Please find enclosed the files for neb2.

Thanks,
Ibrahim

Dear Prof. Henkelman,

Are these results reasonable?

Many thanks in advance,
Ibrahim

Dear Prof. Henkelman,

1- I have attached the mep1 image for one of my systems with 5 images, which related to my previous question where the energy of some images after some ionic steps, is not going down until convergence is reached.

2- For another structure (mep2), I see the energies of images ...

Thank you very much prof. Henkelman.

Yes, it was a run with climbing image NEB.

So now I got it.

Thanks,
Ibrahim

Dear All,

I found that the energy did not go down on some images. why is that happened? is it reasonable?

Many thanks in advance,
Ibrahim

Hi,

For vasp6.3.2, should also:

IF (LCHAIN) CALL chain_init( T_INFO, IO)

be replaced with

CALL chain_init( T_INFO, IO)


?

Thanks

Dear All,

Could you please suggest a solution for bandgap.pl script with output of HSE hybrid functional? This produces a direct band gap of eV. No value is provided for the band gap.

Attached is the OUTCAR.

Many thanks in advance,
Ibrahim

This is the output in my case:


Usage 'bandgap.pl cut=__' where __ is the maximum occupancy to consider a band unoccupied. The default is 0.1

Bands with occupancy less than 0.01 will be considered unoccupied

ISPIN = 2: Spin-polarized calculation

There are bands and k-points
The band gap is ...