Recent Posts

1

Questions and Answers / Re: mismatch in k-point sampling electrode to central region, error code

« Last post by Jess Wellendorff on Today at 10:00 »

looks like error in k-point settings. Number of k-points (k_x,  k_y, k_z) must be identical in electrode calculator and device calculator.

2

Questions and Answers / Device calculation for collinear electrodes

« Last post by bikash on Yesterday at 06:02 »

Dear Sir/Madam,

I want to do device simulation for concentric tubes. Where, my innermost and the outermost tubes act as electrodes. But, I have not been able to carry out the same as for a device simulation, the two ends are automatically considered as electrodes depending upon the size defined by the user.

Hence, could you please help me in this regard.

Thank You.

3

Questions and Answers / Export images in vector format

« Last post by hadi9827 on January 26, 2021, 11:03 »

Hi all,
Is there any way to export images from "viewer" in any vector format?
Thanks.
Hadi

4

Questions and Answers / Noncollinear spin and spin orbital coupling

« Last post by jiejiang on January 25, 2021, 20:32 »

Dear ATK Forum,

I am interested in calculating transport with noncollinear spin and spin-orbital coupling.

I found the relevant tutorial, at
Introduction to noncollinear spin | QuantumATK R-2020.09 Documentation.

In this example, it sets up noncollinear calculation from collinear one.
The only difference is to change initial spin configuration from parallel (or anti-parallel)
to a rotated one.

My questions are

(1) after SCF, will the spin configuration go back to collinear case?
(2) there is one ground state only for carbon chain. The ground state is either collinear
spin or noncollinear. spin. Why can we have both collinear transport and noncollinear transport?
(3) without introducing spin-orbital coupling, we still can get noncollinear spin?
(4) is the spin orbital coupling (SOC) activated by just changing the exchange–correlation method
and pseudopotentials? Is there a paper about how does SOC implement in ATK?

Thanks,

Jie

5

Questions and Answers / mismatch in k-point sampling electrode to central region, error code

« Last post by sabyaphy12@gmail.com on January 24, 2021, 15:38 »

+------------------------------------------------------------------------------+
Traceback (most recent call last):
  File "/home/software/mn-porphyrine/fe2-mn2-fm-thermo1.py", line 618, in <module>
    device_configuration.setCalculator(calculator)
  File "zipdir/NL/CommonConcepts/Configurations/DeviceConfiguration.py", line 1310, in setCalculator
  File "zipdir/NL/Calculators/Interfaces/DeviceCalculatorInterface.py", line 116, in _upgrade
  File "zipdir/NL/Calculators/Interfaces/DeviceCalculatorInterface.py", line 217, in _checkElectrodeKpointSampling
NL.ComputerScienceUtilities.Exceptions.NLValueError: The k-point sampling of the electrode 0 does not match the sampling of the central region.
application called MPI_Abort(MPI_COMM_WORLD, 1) - process 3
~
~
~
~
~
"fe2-mn2-fm-thermo.log" 35L, 2262C         k

6

Questions and Answers / Re: Asking for help; I can not relax a ZnO surface!

« Last post by hadi9827 on January 21, 2021, 12:38 »

The problem has been solved. The 0001 ZnO surface is not stable and needs some modifications to become stable. Just to share what I found out: if anyone is interested in more info, he/she may take a look at the following paper:
http://dx.doi.org/10.1016/j.susc.2012.09.004

Thanks,
Hadi

7

Questions and Answers / Re: Slater-Koster method for charge transfer calculations

« Last post by hadi9827 on January 20, 2021, 15:38 »

Thank you very much for your response. I will do so. Sorry, I asked a new question titled "Asking for help; I can not relax a ZnO slab". Would you mind checking it to help me, please? It has been a week I am trying to solve that problem. Thank you for being supportive

8

Questions and Answers / Re: Slater-Koster method for charge transfer calculations

« Last post by Petr Khomyakov on January 20, 2021, 15:26 »

I do not see anything peculiar in your script. You may try calculating ElectrostaticDifferencePotential for epsilon=1 and epsilon>>1, and compare that for the 2 cases to see if there is any effect of changing epsilon on the electrostatic potential in your calculations. 

9

Questions and Answers / Asking for help; I can not relax a ZnO surface!

« Last post by hadi9827 on January 20, 2021, 10:02 »

Dear all,

I am trying to relax ZnO (10-10),(11-20), and (0001) slabs by using the semiempirical method, Slater-Koster. For (10-10) and (11-20) the calculations are fast and the surfaces are stable and in a good form and everything is reasonable. However, for the (0001) slab, I tried several slabs with different sizes and boundary conditions but the calculations will converge in a very long time (2-3 days!!!) while the surface finally collapses or deforms. I attached the script and a pic. Would you please guide me on what the problem could be and what the solution is? I have been struggling with this for one week, trying any solution I assumed may work 
Thanks.

Hadi

10

Questions and Answers / Re: Slater-Koster method for charge transfer calculations

« Last post by hadi9827 on January 14, 2021, 13:12 »

Thank you very much. I can not see it, so I will do it manually.
Have you checked my script as well? I have no idea why the dielectric constant has no impact on the optimization trajectory. I change it from 1 to 50 but when I check the optimization trajectories the identical things happen. I hoped to see some changes when I change the dielectric constant since I am implementing the molecule in implicit solvent!