Messages

391

Scripts, Tutorials and Applications / Re: how to stop an execution in Job Manager

« on: June 28, 2016, 14:17 »

To elaborate on Anders' point, you should see either "atkpython" or "atkpython_exec" and you can kill this process without "harming" VNL. Thanks for providing information about the operating system. Could you please also write which version of VNL/ATK you are using? I think you have a hit a bug which has been fixed in the upcoming release, but I would like some more information to be sure that it is indeed the same problem.

Also, just to clarify: Does the Job Manager act as if the job is finished, but the job continues running when you look at top? Or is the Job Manager itself unresponsive?

392

Scripts, Tutorials and Applications / Re: how to stop an execution in Job Manager

« on: June 28, 2016, 11:57 »

Please provide more information about your operating system and which version of ATK you are using.

Meanwhile, you should be able to simply kill the process using "kill" in the terminal if you are on linux or through the task manager on Windows.

393

General Questions and Answers / Re: phonon band calculation: length of unit cell must lagre than 4 for Brenner

« on: June 28, 2016, 11:01 »

The implementation of the Brenner potential used in ATK requires a certain distance between periodic images of the atoms. It does not affect the results in any way, and as Anders writes, the Brenner potential is designed for larger systems.

394

General Questions and Answers / Re: To converge optical spectra

« on: June 21, 2016, 10:07 »

It depends somewhat on your system, but we have seen cases where it is necessary to go to more than 30 eV above the Fermi level. There is not a 1-to-1 correspondence between the energy of your photons and the energy range which is necessary to investigate.

395

General Questions and Answers / Re: DensityOfStates and Potential

« on: June 14, 2016, 09:20 »

Please be advised that we will introduce the HartreePotential and HartreeDifferencePotential in 2016, changing the definition of the ElectrostaticPotential and ElectrostaticDifferencePotential by a factor of -e compared to 2015.

Also, the link to the Reference Manual is not the current (2015.1) version, which can be found here: http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html

396

General Questions and Answers / Re: MOS2 nanotube

« on: June 9, 2016, 08:35 »

Please provide the script and a picture of your result, then we are in much better position to help you.

397

General Questions and Answers / Re: convergence of electronic steps

« on: May 25, 2016, 20:45 »

The reason it starts again from 69 is that it has converged at that point. I guess you are making a structural optimization, so this is where it starts the next step of that.

398

General Questions and Answers / Re: Optical spectra k-points

« on: May 11, 2016, 13:33 »

The ideal k-point setting is system dependent, but yes, it is also always dependent on the dimension of the material. Ideally, you should check that the optical spectrum is converged with respect to the number of k-points, and also the number of bands included.

399

General Questions and Answers / Re: Convergence of electronic steps

« on: May 9, 2016, 20:22 »

100 steps is the default number of steps for the SCF loop in ATK, so this means that your calculation, probably, did not converge to the specified tolerance. If you loom directly in the log-file, you will see a warning about this after the 100th step (the count starts from 0).

The reason it stops after 42 in the second iteration is that it has converged to the specified tolerance. This is what you should consider normal behavior.

As the second step converges your calculation might still end up being usable, but I would advise you to check your results carefully, and be very cautious with using results directly from an unconverged calculation.

400

General Questions and Answers / Re: Stanene Structure

« on: May 3, 2016, 09:45 »

In the Builder, you can use Add -> From Plugin -> Nanosheet and put in Tin and the suggested lattice parameter. You might need to break the symmetry by hand (using e.g. the Move tool) in order to achieve the buckling, as the created structure will be perfectly flat.

401

General Questions and Answers / Re: Formtion Energy Tutorial Source code

« on: May 2, 2016, 09:07 »

Not at the moment, but if you tell me what you need more specifically, I can probably find or make it for you. We expect to update the tutorial in the near future.

402

General Questions and Answers / Re: Chemical potential for the surface energy calculations

« on: April 26, 2016, 14:40 »

Just to clarify: Jess is explaining what is meant by ChemicalPotential in ATK - here it is always for the electrons. Of course you can talk about the chemical potential of other species, but there is no specific functionality to calculate that in ATK.

403

General Questions and Answers / Re: Guide on how to relax a device system

« on: April 20, 2016, 15:26 »

It looks like you might have changed the element of some of the atoms to something not supported by the potential. Do you do the tutorial exactly as it is written or have you made modifications? In the latter case, please provide your scripts.

404

General Questions and Answers / Re: calculate Density of state (DOS) using DFT

« on: April 20, 2016, 08:59 »

There is no spcific tutorial for calcualtiong the Density of States, but it is included in these tutorials: docs.quantumwise.com/tutorials/sic_bandstructure.html and docs.quantumwise.com/tutorials/nisi2-si.html

405

General Questions and Answers / Re: calculate electron density

« on: April 18, 2016, 11:23 »

Yes, see for example this tutorial: docs.quantumwise.com/tutorials/sic_bandstructure.html