Messages

16

General Questions and Answers / Re: monolayer MoS2 electron affinity calculation

« on: June 29, 2019, 10:42 »

Thanks for the confirmation!

17

General Questions and Answers / Re: monolayer MoS2 electron affinity calculation

« on: June 27, 2019, 02:31 »

Thanks for your response.

So, if we use plane-wave basis,  we don't need ghost atom and setting up boundary conditions (top side of supercell to Dirichlet, bottom side of superccell to Neumann) would give a right chemical potential.
Is this right?

Thanks.
jiwon

18

General Questions and Answers / Re: monolayer MoS2 electron affinity calculation

« on: June 24, 2019, 12:47 »

I see. Sorry for not to be clear on the question.
Let me specify it.

So, in the example of Ag work function calculation as below
https://docs.quantumwise.com/tutorials/work_function_ag_100/work_function_ag_100.html#work-function-ag-100

It set up one Ag atom as a ghost.

To do the same thing on monolayer MoS2, I put atoms as follows

vacuum Mo-S-Mo-Mo(ghost atom) vacuum

Monolayer Mo-S-Mo is there and one Mo atom is placed on one side of MoS2.
Then, here what could be the good distance between MoS2 and ghost Mo atom? Any distance would be fine?
One more question is
Do I need to run relaxation calculation (relaxing Mo-S-Mo and fix ghost Mo atom)?
If I have relaxed Mo-S-Mo (monolayer MoS2), then placing one ghost Mo atom requires another relaxation?

Thanks.
jiwon

19

General Questions and Answers / Re: monolayer MoS2 electron affinity calculation

« on: June 24, 2019, 11:28 »

Thanks for your response.

I ran it and found the obtained affinity is same with what I could get from other experiment and calculations of monolayer MoS2.
But, this one does not guarantee that my approach is right. As mentioned in the one of the link in my original post, we can get the value from the wrong approach. That is why I ask an expert's advice.

jiwon

20

General Questions and Answers / monolayer MoS2 electron affinity calculation

« on: June 19, 2019, 04:27 »

Hi

I tried to calculate the electron affinity for monolayer MoS2.
I used informations which I could find in the link below.
https://forum.quantumatk.com/index.php?topic=5270.msg23352#msg23352
https://forum.quantumatk.com/index.php?topic=5114.msg22147#msg22147
https://docs.quantumwise.com/tutorials/work_function_ag_100/work_function_ag_100.html#work-function-ag-100

I want to confirm that what I did is right.
I introduce one sulfer ghost atom and set the boundary conditions as mentioned in the tutorial.
Then, I ran chemical potential calculation.

I attatch my script file here. Please take a look and let me know if this approach is right.

Thanks.
jiwon

21

General Questions and Answers / 2D rectangular Contour plot

« on: October 19, 2018, 11:16 »

Dear,

The attachment py file is about Hexagonal contour plot (conduction band).
I want to know how to make "rectangular" contour plot.


Thanks
jchang

22

General Questions and Answers / Re: Adjusting energy grid in DOS calculation

« on: March 8, 2018, 03:50 »

Thanks!

23

General Questions and Answers / Adjusting energy grid in DOS calculation

« on: March 7, 2018, 05:09 »

Hi,

I want to increase the resolution for DOS calculation.
But, it seems that it is not supported.
Is there any way to manually put the dE, Emax and Emin for DOS?

Thanks.
jiwon

24

General Questions and Answers / Re: energy contour plot for band structure

« on: January 25, 2018, 23:55 »

HI Anders,

It matches pretty well.

I tried other materials to plot contour plots. I could see those kind of notched contour  in other materials.
I have tested PBE/GGA/FHI. Will try with other options.

jiwon

25

General Questions and Answers / Re: energy contour plot for band structure

« on: January 24, 2018, 23:31 »

In the paper, they matched TB with DFT shown in Fig 1.
Almost same TB band structure with DFT.

It is enough for me if I can confirm that the difference could be caused by interpolation.

Thanks.

26

General Questions and Answers / Re: energy contour plot for band structure

« on: January 23, 2018, 23:57 »

Thanks for your input.

Yes, it looks pretty much same. But along G to M line, I think contour line around M is orthogonal to line connecting G and M in paper.
But in my figure, it seems not (it is notched). So I suspected something is wrong in interpolation or in my calculation itself.

Thanks.
jiwon

27

General Questions and Answers / Re: energy contour plot for band structure

« on: January 23, 2018, 22:45 »

Hi,

What I want to reproduce is shown here.
http://ieeexplore.ieee.org/abstract/document/8110697/

In Fig3(c) and (d), valley looks ellipsoidal.

Please give me some advices.

Thanks.
jiwon

28

General Questions and Answers / Re: energy contour plot for band structure

« on: January 22, 2018, 23:03 »

Hi, Anders

I tried to reproduce result reported in literature.
Would it be good to try other pseudopotentials and basis sets?


jiwon

29

General Questions and Answers / Re: energy contour plot for band structure

« on: January 22, 2018, 08:04 »

Hi Ander,

I could successfully modify your scrip for contour plot.
But I have one question for you.

In the attached contour plot, I plotted CB and there are six CB minimum valleys along Gamma to M.
For those valleys, I expected ellipsoidal contour plots, but as shown in the plot, contour line is getting sharper along G to M lines.
And same things around M point, I expected ellipsoidal contour plots, but what I see is somewhat sharp points along G to M.

I think it could be an error from interpolation.
I did band structure calculations with dense k points, but no change.

Do you have any ideas about this?


Thanks.
jiwon

30

General Questions and Answers / Re: energy contour plot for band structure

« on: January 19, 2018, 13:01 »

Thanks! I will try the script you posted there.

jiwon