Recent Posts

1

General Questions and Answers / Re: Information and Capabilities of Pretrained MTPs in Force Field Library for MD

« Last post by msingh96 on Yesterday at 22:56 »

Hi Anders, I've been trying to figure this out on my own before posting again.

I am trying to use the Si/TiSi₂ potential for MD simulations. I have had modest success with small structures, but the most frequent error is atoms leaving the simulation cell. this error causes the MD simulation to stall and get stuck. my instinct is an issue with the structures I provided, I used the interface builder to make an initial structure with Si [100] surface and TiSi[001] surface but I have to manually modify the distance between the surfaces using shift surface. I want to equilibrate the surface distance suing NPT but that's not working either.

Are there any example geometries from the training data for this potential to see where I'm going wrong?

2

Installation and License Questions / Re: Is there any limitation for number of execution of Simulation?

« Last post by Anders Blom on May 24, 2024, 18:30 »

Could be. Finished just means the job is not running any more, but the Job Manager does not know anything about possible errors that arose.

3

Installation and License Questions / Re: Is there any limitation for number of execution of Simulation?

« Last post by techenthusiast on May 24, 2024, 08:55 »

Also there is a small doubt: Sometimes its showing Job status as "finished" even ongoing execution for example ("Executing task - 7/20")  . Without throwing any error. Its similar to this?

4

Scripts, Tutorials and Applications / Re: spatial region extended into the centre region, not calculated during electrode

« Last post by techenthusiast on May 24, 2024, 05:53 »

Thank You for your kind advise. The system is a metallic wrap around gate across the central region (Channel).

Like this (Device_setup.py) -https://docs.quantumatk.com/manual/Types/IVCharacteristics/IVCharacteristics.html#usage-example

For tutorial I was following this (Top & bottom metallic box gate) -https://docs.quantumatk.com/tutorials/ivcharacteristics/ivcharacteristics.html

That's why probably I was bit confused  regarding the approach -whether it is same or not for both the cases.

Thank you once again. 

5

Scripts, Tutorials and Applications / Re: spatial region extended into the centre region, not calculated during electrode

« Last post by Anders Blom on May 24, 2024, 00:58 »

The IVCharacteristics framework is handy since it is restartable and provides a nice way to loop over all bias values and gate voltages. If you have multiple gates or a more complex system I recommend just running individual simulations or a script with a loop over values, and then collect the results in the end.

6

General Questions and Answers / Re: Missing SK Parameters from Install

« Last post by Anders Blom on May 24, 2024, 00:56 »

Yeah sorry, we removed this model because it was not giving good results. We forgot to update the tutorial. You will have to run with DFT instead, you can use the smallest basis set FHI/SingleZeta to get fast results, probably similar accuracy as DFTB.

7

General Questions and Answers / Re: Interfering and non-interfering contributions of the transmission function

« Last post by MolFET93 on May 23, 2024, 13:06 »

Thank you! I'll give a try.

8

Scripts, Tutorials and Applications / Re: spatial region extended into the centre region, not calculated during electrode

« Last post by techenthusiast on May 22, 2024, 10:34 »

Thank You for your prompt response. One small doubt is that -
In this example ( https://docs.quantumatk.com/tutorials/ivcharacteristics/ivcharacteristics.html ) we can visualize the explanation for two sided [top, bottom] gate & dielectric

But the procedure for IV study for cylindrical wrap around gate is similar to this? or maybe different or maybe do-able with the same above tutorials

(https://docs.quantumatk.com/manual/Types/IVCharacteristics/IVCharacteristics.html#usage-example)

Kindly advise. Thank You very much once again.
 

9

Scripts, Tutorials and Applications / Re: spatial region extended into the centre region, not calculated during electrode

« Last post by Anders Blom on May 21, 2024, 20:48 »

Spatial regions are not supposed to be contacts, since they will not be able to conduct hold any current. They are only meant to be used for electrostatic control, like gates. Your source and drain need to be fully atomistic structures which are part of the DFT-NEGF calculation.

10

General Questions and Answers / Re: Information and Capabilities of Pretrained MTPs in Force Field Library for MD

« Last post by Anders Blom on May 21, 2024, 20:30 »

If you go outside the domain where the potentials are trained you can easily see such effects, yes. Which MTP in particular are you trying to use?