Messages

1

General Questions and Answers / Re: Forcefield potential for dopant diffusion simulation in Si

« on: February 20, 2023, 10:07 »

I see. Thanks for your response.

jiwon

2

General Questions and Answers / Forcefield potential for dopant diffusion simulation in Si

« on: February 19, 2023, 06:56 »

Hi all,

I try to simulate typical dopant diffusion (B, P, As) in Si, SiGe, and Si/SiGe heterostructure.
I consider to use MD simulation, but I could not find any good potentials.
Then, is the only approach that I can use creating ML-FF?
Please give me any advices on this.

Thanks.
jiwon

3

General Questions and Answers / Re: PackMole file for amorhpous HfO2 structure

« on: February 18, 2023, 04:47 »

Thanks for your answer.

jiwon

4

General Questions and Answers / Re: PackMole file for amorhpous HfO2 structure

« on: February 3, 2023, 04:14 »

Hi,

In my previous post, I asked amorphous HfO2 structure generated by PackMole.

I think we can also use the amorphous HfO2 structure generated by regular MD simulation in the below link.
https://docs.quantumatk.com/tutorials/amorphous_structures/amorphous_structures.html

Can anyone confirm this?

Thanks.
jiwon

5

General Questions and Answers / PackMole file for amorhpous HfO2 structure

« on: February 1, 2023, 13:19 »

Hi all,

I was studying mtp generation for HfO2.

https://docs.quantumatk.com/tutorials/mtp_hfo2/mtp_hfo2.html

In the step 2, we need amorhpous structure for active learning.
And the amorphous HfO2 is first generated using PackMole followed by FF based geometric optimization.

Can I get the script for the initial HfO2 structure generation using PackMole?
Of course, if I could get the FF optimization file as well, that will be even better.

Thanks.
jiwon

6

General Questions and Answers / meaning of energy cutoff value for LCAO DFT calculation

« on: November 12, 2020, 09:35 »

Hi,

I have a basic question about energy cutoff.
Basically, energy cutoff defines the energy limit for plane wave basis set.
Then, what is the meaning of energy cut off if I use LCAO basis set for DFT?
Can anyone explain this?

Thanks.
jiwon

7

General Questions and Answers / Re: Ge Bandstructure pps-PBE

« on: October 12, 2020, 01:44 »

Thanks Anders. It works!

8

General Questions and Answers / Ge Bandstructure pps-PBE

« on: October 7, 2020, 08:58 »

Hi,

I have a question on Ge band structure calculation shown in this link.
https://docs.quantumatk.com/tutorials/dft_half_pps/dft_half_pps.html

I tried to follow the calculations using files (bulks.py, pbe.py, pps.py) which I can download from the above link.
I could run pbe.py, but I got into licence error issue when I tried to run pps.py which is for adjusting the Ge band gap.
To run pps-DFT, do we need a special license for ATK?

Can you please give me any advices on this issue?

Thanks.
jiwon

9

General Questions and Answers / Unit of Transmission

« on: January 28, 2020, 13:38 »

Hi

I have question about the unit of transmission which we get from the transmission calculation.
Let's say that we have periodic structure in transverse direction like an example below.
https://docs.quantumatk.com/tutorials/transmission_gr_mos2/transmission_gr_mos2.html
And I want to calculate current/width [A/um].
Then, the transmission that I get from the calculation in the above example should be divided by the width of real space unit cell. (of course, I need to multiply it with e^2/h)
Am I doing right?
I just want to confirm the dimension of the transmission that I get from quantum ATK.

Thanks.
jiwon

10

General Questions and Answers / SCF converge issue in Optimization

« on: September 25, 2019, 23:59 »

Hi

I am trying to do geometry optimization of a certain 3 layers of 2D materials.
I have issue in the scf convergence.
To resolve the scf convergence issue, I tried to increase k point and energy cut off. But both didn't work for my case.
I attached my input file of 9x9x1 k point and output log file.
In the first several scf loop converge, but it fails.
I have tested increased k point, but the result is same.

Please give me any advices to solve scf issue in optimization.

Thanks.
jiwon

11

General Questions and Answers / Re: work function of bulk material

« on: August 30, 2019, 04:23 »

I see.  Thanks for your response.
Do you mean that quantumATK cannot calculate work function for bulk?

12

General Questions and Answers / Re: work function of bulk material

« on: August 28, 2019, 09:26 »

Thanks for the quick response.
Then, for the bulk work function calculation, do I need to set up a thick slab to mimic the bulk and then do the work function calculation?

13

General Questions and Answers / work function of bulk material

« on: August 28, 2019, 07:02 »

Hi,

I want to know how to calculate the work function of bulk material.
ATK tutorial about calculating work function is for slab structure having vacuum. And it seems that vacuum is required to set a energy reference.
However, in bulk system, since we don't have vacuum, it is hard to set up any reference by setting up boundary condition.
So, can  we calculate work function of bulk material with ATK?

Thanks.
jiwon

14

General Questions and Answers / Re: unit of transmission spectrum and DOS

« on: July 9, 2019, 10:30 »

Thanks for the fast response.
So, you are saying that the transmission and DOS value from ATK is not normalized by length or area.

Thanks.
jiwon

15

General Questions and Answers / unit of transmission spectrum and DOS

« on: July 9, 2019, 08:15 »

Hi,

I have a question about the unit of transmission in the example below.

https://docs.quantumwise.com/tutorials/transmission_gr_mos2/transmission_gr_mos2.html

In this example, we calculate transmission of rectangular unit cell of graphene and MoS2.
In the graphene example, it shows how transmission spectrum changes with the number of k-points in the transverse modes.
And my question is what is the unit of Transmission.
Since it is a periodic structure in the transverse direction, transmission unit should be #/m or #/um, but the picture showing transmission it is not clear.

Is the default unit in the transmission spectrum just # or #/m?
If it is just #, then I guess we need to divide it with the length of rectangular unit cell in the transverse direction (y-direction).


I also have similar question for DOS calculation.
If I calculate DOS for 2-D material, then the unit for the calculated DOS in ATK is just #/eV or is it normalized with area?

Thanks.
jiwon