Messages

1

General Questions and Answers / Re: Xc functional

« on: August 29, 2023, 20:43 »

hi,
If you are studying system A, then a comparison of Transmission calculated using different XC functional should help you understand the reliability of your results.

2

General Questions and Answers / Re: Xc functional

« on: August 29, 2023, 08:45 »

Try getting Transmission using hybrid HSE06. Should be enough for validation at in the least sense .

3

General Questions and Answers / Re: Geometry optimization issue

« on: July 19, 2023, 02:48 »

Hi
I would still recommend increase K points to at least to 3x3. Maybe it will help.

4

General Questions and Answers / Re: Geometry optimization issue

« on: July 16, 2023, 21:35 »

Hi,
Although I am not sure if this is the right way for magnetic materials but here is the following:
1. Try first optimizing using unpolarized spin GGA.PBE then use optimized geometry to optimize for spin polarized, SGGA.PBE.
2.  Increase your k points. (1x1x1 is very low)
3. Reduce damping_factor to 0.01 and increase max_steps=300
4. Keep max_step_length as default.

5

General Questions and Answers / Re: Electrode and electrode extension size

« on: July 16, 2023, 21:19 »

Hi,
Can you check the case where you observe an increase in electrode length when increasing electrode extension length. In that case, is there a distortion/grain boundary kind of thing at the interface between electrode extension and electrode?

6

General Questions and Answers / Re: Convergence problem in electron transport for silicon electrode system

« on: July 16, 2023, 21:15 »

Hi,

Did u try damping 0.01 with history steps 20? Try it, if you haven't yet!
It may work.

Also, what is ur electrode extension length? Is it doped or undoped?

7

General Questions and Answers / Transmission with Different electrodes

« on: June 5, 2023, 11:15 »

Dear Admin,
I want to calculate zero-bias transmission with different electrodes. I am not an expert at Quantum Transport but will the transmission spectrum depend on the direction of transmission i.e from left to right electrode or right to left electrode?

And how does ATK calculate zero bias transmission?
And how to calculate transmission from left to right and right to left?

8

General Questions and Answers / Re: DFT calcualtions using LCAO

« on: May 1, 2023, 20:04 »

DFTD3

9

General Questions and Answers / Re: DFT calcualtions using LCAO

« on: April 11, 2023, 17:40 »

That is not possible as it gets very expensive computationally to optimize with BSSE. That is suitable for molecules on surface not interfaces with large number of atoms, I guess.

10

General Questions and Answers / DFT calcualtions using LCAO

« on: April 10, 2023, 14:07 »

Dear admin,

Are DFT calculations using ATK LCAO calculator reliable for interfaces between 2D materials such as WS2 and Gold?
I have seen some discrepancies between interfacial distances calculated from VASP using plane-wave and ATK using LCAO.

11

General Questions and Answers / Re: QATK unable to read files

« on: March 30, 2023, 09:04 »

Thanks for your response.

12

General Questions and Answers / Re: Medium basis set for PseudoDojo Pseudopotentials

« on: March 27, 2023, 10:11 »

This is just a basis set created by QATK to optimize for speed and accuracy in DFT calculations. You can look at the paper "QuantumATK: an integrated platform of electronic and atomic-scale modelling tools"

13

General Questions and Answers / QATK unable to read files

« on: March 25, 2023, 12:10 »

Dear ADmin,

I have observed that sometimes QATK is unable to read files upon restarting as shown below in the attached pic.

This has happened many times. Please let me know what is the issue?

It also shows some source scanning error. More than 100000 files in /directory

14

General Questions and Answers / Machine Learning Prerequisites

« on: March 23, 2023, 09:35 »

Dear Admin,

To work with ML force fields provided in QuantumATK, what are the prerequisites required to begin with?
Is there any background course/subjects one should be familiar with?
Also, can you recommend any course to start with?

15

General Questions and Answers / Re: Two Reactive ForceField

« on: January 18, 2023, 07:11 »

Thanks