Messages

1

General Questions and Answers / Strange Band-structure of ZrSe2

« on: June 24, 2017, 10:07 »

Hello Guys,

I have tried to get bandstructure of ZrSe2. Something strange happened (Please look at image precisely, you will see VBM is higher than CBM).
could you help me to get right bandstructure with 0.498eV bandgap. 

I attached images and Python file.
I simulated two times with different value, however, both simulations did with GGA/PAW/PBE
One simulation run with 150 Hartree and 89 k Sampling. the other one with 75 Hartree 41 K sampling. If you check both images you will see similar results

If you need extra information, Please let me know

Thanks in advanced

2

General Questions and Answers / Re: Some thing wrong with MoTe2 calculations ?!!!!!!!!

« on: June 24, 2017, 09:38 »

Dear Petr,

You help me a lot . Thank you   

3

General Questions and Answers / Re: Some thing wrong with MoTe2 calculations ?!!!!!!!!

« on: June 22, 2017, 17:05 »

Dear Petr,

I attach the file I am trying to simulate.  I  also am using 2016.3 version.


Regards

4

General Questions and Answers / Some thing wrong with MoTe2 calculations ?!!!!!!!!

« on: June 22, 2017, 12:09 »

Hello Dear,

I am trying to get band structure of MoTe2( expected to see roughly 1.07 eV bandgap) well something wrong with simulation. I am asking for some guidance after simulations of two different type of MoTe2(1 from ATK database, 1 From MaterialProject).
Back to My question,
I have chosen MoTe2 1.1.1 (GGA/PAW/PBE), cutoff 75Hartree and 41K sampling. I saw that pseudopotential of Mo by default is FHI/Ti0 (interesting) so to ease the calculation I changed Te to the same thing. Optimization part I chose : Maximum step 200 and Tolerance 0.01 e/V and 0.01 e/V^-3 .

After 1.5 days, MoTe2 simulation is in the 44 step, it has not stopped yet. when I look at MoTe2 video precisely (.tar file I mean) 2 atom of Te come much closer to each other which is strange. I had MoS2 or even MoSe2 bandstructure less than 24hrs. what is wrong with its?

If I need to provide more information please let me know.

Thanks in advanced 

5

General Questions and Answers / Re: MoS2 bandstructure

« on: June 7, 2017, 12:42 »

Dear Jess,

Thanks for your reply.
I have another question.  Pristine MoS2 is n-type, am I right? So If yes,  why I got p-type? :-(
 
If you look precisely into attached file you will see I have right bandgap but confused with n-type , p-type.

6

General Questions and Answers / Re: ZrS2

« on: June 6, 2017, 17:17 »

Thx 

7

General Questions and Answers / MoS2 bandstructure

« on: June 6, 2017, 17:17 »

Hey Dear,

It would be great if someone can help me to understand MoS2 bandstructure and the rest of 2D materials theory.
You are wondering what I am looking for? Well, we know Monolayer MoS2 is n-type So, how I got right bandgap value but p-type. ? if I am right n-type or p-type structure means  Ef located near conduction or valence band, but My graph shows Ef located in the middle.  why?
 
I used 1.1.1 to get MoS2 bandstructre. LDA-PZ
If you need extra information please let me know.


Thanks in advanced.

8

General Questions and Answers / Re: ZrS2 bandstructure

« on: June 6, 2017, 13:33 »

Thx

9

General Questions and Answers / Re: ZrS2

« on: May 30, 2017, 09:02 »

actually, I have added U to get similar GGA+U but I haven't get the same result. First, I am trying to understand bandstructure difference without U.

Unknown point left for me  is that I simulate 1.1.2 everything looks Ok (not same but similar subband structure with reported bandstructure, I know affect of U) but when I simulate 2.2.2 I get extra 2subband at conduction band and valence band locate at lower position than 1.1.2. Why?

Please Look at my picture. You will see extra subband and the difference between them, I am trying to understand why extra subband ?what effect on 2.2.2 structure to get different band structure?

Thanks

10

General Questions and Answers / Re: ZrS2

« on: May 30, 2017, 08:33 »

Dear Anders,

From what I have seen from ZrS2 bandstructure, Does it make sense that Conduction and Valance band  Value of 1.1.2 , 2.2.2 are different alot?  You know I am surprised with my results because I saw bandgap value of 1.1.2 , 2.2.2 is totally different and also extra subband at Conduction band when I simulate 2.2.2? Why? Help  me plz.

also if you look at https://www.researchgate.net/publication/279865763_Semiconductor-to-metal_phase_transition_in_monolayer_ZrS2_GGAU_study , you will see reported bandgap is totally different with my simulation(However I follow their structure to simulate ZrS2)


if you need more information to help me how I figure out my problems please let me know,
Thanks

11

General Questions and Answers / ZrS2

« on: May 29, 2017, 13:21 »

Hey guys
I am trying to simulate ZrS2 monolayer. Actually, I tried many times last week to get its band structure.

Bandstructure of 1*1*2 is different with 2*2*1. My question is how I am able to get same band structure?

I used GGA/PBE/DZP with ecut off 75Hartree and sampling 60.60.1 for my calculation.

Please look at my attached files and let me know what's wrong with my results.


Thanks in advanced.

12

General Questions and Answers / ZrS2 bandstructure

« on: May 29, 2017, 08:56 »

Hey guys
I am trying to simulate ZrS2 monolayer. Actually, I tried many times last week to get its band structure.

Bandstructure of 1*1*2 is different with 2*2*1. My question is how I am able to get same band structure?

I used GGA/PBE/DZP with ecut off 75Hartree and sampling 60.60.1 for my calculation.

Please look at my attached files and let me know what's wrong with my results.


Thanks in advanced.

13

General Questions and Answers / Re: 2D material Bandstructure

« on: May 8, 2017, 15:47 »

thx dear petr

The problem solved.

14

General Questions and Answers / Re: 2D material Bandstructure

« on: May 8, 2017, 11:59 »

well, your r right .

to be more precise about my question.
just think about MoS2 1L and MoS2 2L. I am looking to analysis this material and to be able to see bandstructure of it.
I also go further and more layer what I mean by saying this is that MoS2 2L, WS2 1L, and BN 1L. how do you think I am able to do this?

15

General Questions and Answers / Re: 2D material Bandstructure

« on: May 8, 2017, 11:06 »

Thx Dear Petr
great links to more practice

I have done most of the tutorial stuff. I am familiar with the software . I am looking to know how to introduce a new element to a database. have you simulated any elements to get bandstructure for single layer and double layers? any comments