Recent Posts

1

Questions and Answers / Re: Use of Hybrid functional in device calculation with spin-orbit interaction

« Last post by sumitn60 on September 17, 2021, 10:43 »

Hi Ulrik,

Thanks for your information.

Waiting for the next release soon!

Thanks again

Sumit

2

Questions and Answers / Re: Use of Hybrid functional in device calculation with spin-orbit interaction

« Last post by Ulrik G. Vej-Hansen on September 17, 2021, 10:36 »

Hi Sumit

NEGF calculations with hybrid functionals and spin-orbit is not yet supported, but it is planned and we hope to include it in the next release.

Best regards
Ulrik

3

General Questions / << script to decorate/functionalize nanotube >>

« Last post by Camps on September 16, 2021, 20:44 »

Hello,

I would like to know if there is any plugin or known script that permit the decoration or functionalization of nanostructures.

I am thinking in having a carbon nanotube, and randomly adding a functional group like -OH specifying the functionalization percentages, for example.

Regards,

Camps

4

Questions and Answers / Re: xsf or axsf format file

« Last post by Anders Blom on September 16, 2021, 20:22 »

A few specific data types might be possible to import, like charge density, but we are not putting much priority on interfacing other packages these days, to be honest, especially after we implemented our own plane-wave basis set, and have a much more efficient HSE model in LCAO than you can even find in plane-wave.

So it's much easier to calculate these with QuantumATK, then you can visualize anything you want :-)

5

Questions and Answers / Re: Raman spectra calculation

« Last post by Tue Gunst on September 16, 2021, 17:29 »

I assume that the mechanism that you refer to is the peak position shift in Raman peaks?
The Raman peaks will shifts position due to anharmonic effects with temperature.
The best option currently would be to perform MD for a supercell to include anharmonic interaction.
In general, ensemble averaging the Raman spectra should do the job but that will of cause be computational heavy for a supercell.
A better solution would be to calculate anharmonic shifts in the phonon frequencies directly. QuantumATK currently doesn't support that but it is in the pipeline so stay tuned.

6

Questions and Answers / Use of Hybrid functional in device calculation with spin-orbit interaction

« Last post by sumitn60 on September 16, 2021, 14:03 »

Hi,

I was trying to calculate IV characteristics for molecular junction in LCAO calculator, the spin-orbit coupling (non-collinear) is implemented in the LCAO calculator for pure functional. My question is it possible to do transport calculation with spin-orbit coupling in molecular junction with hybrid functional like HSE06? Because when I'm selecting hybrid functional calculation the calculator is automatically changed itself to the Unpolarized configuration. Is there any way out or I'm making something conceptually very wrong?

Waiting for your quick response!

Thank You

Sumit

7

Questions and Answers / Re: xsf or axsf format file

« Last post by Roc2019 on September 16, 2021, 13:38 »

Thank you Dr. Blom.

I want to view the xsf or axsf files inlcuding the charge density, vibrational mode, etc.  It seems that the 2020.09.sp1 can not read them.  In addition, it could be better to read or set the Fermi energy of QE output, then the shown band structure (energy zero point) in VNL is relative to the Fermi level.

Thanks.

Roc

 

8

Questions and Answers / Re: xsf or axsf format file

« Last post by Anders Blom on September 15, 2021, 21:18 »

Are you thinking of full output files to analyze e.g. the electron density, or you just want to get the atomic structures?
QuantumATK can already read the native QE output files, see https://docs.quantumatk.com/tutorials/espresso_bs_dos/espresso_bs_dos.html

9

Questions and Answers / Re: OSError: Unable to open file

« Last post by Anders Blom on September 15, 2021, 21:13 »

Looks like the Job Manager settings file(s) have been corrupted somehow. Unfortunately this happens now and then, and can usually be resolved by removing the "job" files in $HOME/.vnl/job_manager_<version>, and if that doesn't work try to also remove the "state.hdf5" file.

10

Questions and Answers / Re: The setting of Interatomic

« Last post by Anders Blom on September 15, 2021, 21:09 »

Chemical bonding is a surprisingly loosely defined concept! On the input side, in DFT we don't even need bonds for the calculation, only the atom positions.

On the output side, to analyze chemical bonding there are multiple models and theories in the literature, each one having advantages and disadvantages, and yielding slightly different results.

The closest built-in function we have is the Mulliken bond populations (see https://docs.quantumatk.com/manual/Types/MullikenPopulation/MullikenPopulation.html#notes) which at least can give a hint about the degree of bonding between different atoms; also you could quite easily implement Löwdin overlap populations in a script. But more advanced analysis of the type where you break up the electron density into atomistic contributions and use that to ascribe bond strengths etc is not implemented.

What exactly were you looking to compute for your cases, ainunK?