Messages

376

General Questions and Answers / Re: processes_per_kpoint in 2016 version

« on: August 25, 2016, 13:18 »

The value of processes_per_kpoint depends on the number of k-points you use, but in 2016 it is now determined automatically. So unless you find that the default parallelization scheme is sub-optimal for your system and cluster setup, it should not be necessary to manually set processes_per_kpoint.

377

General Questions and Answers / Re: supercell

« on: August 23, 2016, 09:58 »

It depends on what you want to model. In the tutorial you link to, the purpose is to have one side of the slab model a real surface, and the rest is supposed to model bulk. In this case it is correct to do as written in the tutorial and constrain the bottom two layers.

In other cases you might want to use both sides of the slab as models for a surface, and in this case it could make sense to constrain the layers in the middle, but in general this would probably require a much thicker slab.

378

General Questions and Answers / Re: non-adiabatic molecular dynamics

« on: August 16, 2016, 19:42 »

No, that is unfortunately not implemented. You are welcome to make a feature request in the "Future Releases" section of the forum.

379

General Questions and Answers / Re: structure of graphene

« on: August 4, 2016, 13:53 »

Please see this tutorial: docs.quantumwise.com/tutorials/exploring_graphene/exploring_graphene.html

380

General Questions and Answers / Re: visualizing vacancy movement.

« on: July 22, 2016, 10:12 »

The procedure Anders describes is shown in this tutorial: http://docs.quantumwise.com/tutorials/akmc-empirical-sige.html

381

Scripts, Tutorials and Applications / Re: refractive index

« on: July 21, 2016, 09:20 »

Please search before you post - this exact question was answered less than three weeks ago in a thread with almost exactly the same title:

http://quantumwise.com/forum/index.php?topic=4213.msg19228#new

382

General Questions and Answers / Re: Global minimum for bulk-reg

« on: July 14, 2016, 16:06 »

Have you done a structure optimization? It is not possible to tell whether it is at the global minimum from just the data in your post, so please provide also the script you have used.

383

General Questions and Answers / Re: Mobility calculation in ATK

« on: July 12, 2016, 11:09 »

In short: No, the relaxation time is not independent of the functional. The relaxation time depends on the electron-phonon coupling, as shown in equation 5 in the tutorial, and this will always depend on the functional. However, it is difficult to say a priori whether that dependence is strong or not.

384

General Questions and Answers / Re: VibrationalMode

« on: July 12, 2016, 09:13 »

If you use the python interface you can get a trajectory file for a certain vibrational mode by using the "movie" method, as described here: http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.vibrationalmode.html

Is that what you need?

385

General Questions and Answers / Re: indium tin oxide clusters

« on: July 12, 2016, 09:07 »

If you find suitable parameters for InSnO in the literature, you can add them manually as described in this tutorial: http://docs.quantumwise.com/tutorials/combining_potentials.html

However, note that the potential must be of a type that is already implemented in ATK (e.g. Tersoff, EAM etc.)

386

General Questions and Answers / Re: Mobility calculation in ATK

« on: July 11, 2016, 14:42 »

The reason for the error you get is that mGGA is not implemented for force calculations, which you need for the dynamical matrix. Please see the Reference Manual for further details: http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/chap.atkdft.html

387

General Questions and Answers / Re: Box on top of any S.C. surface

« on: July 8, 2016, 14:13 »

Could you please specify what you mean by "S.C. surface" ?

388

General Questions and Answers / Re: Atomic positions of strained Si lattice by adding Ge

« on: July 5, 2016, 11:51 »

In that case, you need to do a GeometryOptimization with your chosen computational model, both before and after inserting the Ge. This procedure is described in the beginning of this tutorial: http://docs.quantumwise.com/tutorials/formation_energies.html

You can then get the coordinates directly from the output of the calculations or extract them from the BulkConfiguration afterwards.

389

General Questions and Answers / Re: Atomic positions of strained Si lattice by adding Ge

« on: July 5, 2016, 10:32 »

Would you like to calculate the new equilibrium lattice constant, or simply extract the coordinates? The latter is done in exactly the same way also after you substitute the Ge.

390

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

« on: June 29, 2016, 21:10 »

Thanks for the update. It sounds like it is a known bug which will be fixed in the upcoming release. Until then, you can kill the process "atkpython_exec" using the "kill" command from the terminal. This way you should not need to restart your computer.