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Topics - MaryamNazirfakhr

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1
General Questions and Answers / proper basis sets of extended Huckel, for hexagonal BN-C nanoribbons
« on: December 12, 2015, 23:17 »
Hello   :)

I would like to know that ,what are the proper basis sets of extended Huckel, for hexagonal BN-C nanoribbons?

Regards

2
General Questions and Answers / van der waals correction
« on: November 30, 2015, 10:14 »
hello

i'm trying to optimize "billayer Boron nitride (BN) nanoribbon" and "billayer Boron nitride-Carbon (BNC) nanoribbons ". I need to use PBE+vdW approach. but i don't have enough information about the parameters of "van der waals" icon in ATK2015.

1.could you please help me by some explanation or a tutorial?
2. What is your recommendation for better and faster optimization of such a structure?

one more question. I run the simulation, and then i click on log icon which is below the menu bar in job mannager in order to see the code running. when the log page opens, sometimes the log page is blank during the simulaton. sometimes I can see the code running but it suddenly stops (of course just the code in log page and not the simulation itself).could you please tell me that how can i fix this problem?

Thanks a lot

3
General Questions and Answers / ZGNR-BNNR structure and optimization
« on: November 23, 2015, 22:30 »
Hello

I use ATK2013. I'm trying to build a unitcell of a 8ZGNR-4BNNR hybrid nanoribbon.
1. Once I used the "merge" tool, in order to merge 8ZGNR and 4BNNR, and then I optimized the whole 8ZGNR-4BNNR unitcell.
2. I created a 12ZGNR, then I changed 2 dimer lines of C atoms to B and N atoms (4BNNR), finally I optimized the whole   8ZGNR-4BNNR unitcell.

I have 3 questions:
1. I would like to know that which one of the mentioned methods is  more recommended?
2. what is the lattice constant for a ZGNR-BNNR structure? (when i used the first method, the lattice constant was 2.505, and by the second method it was 2.46. )
3. I use DFT for optimization. I set cut-off and k-point sampling to 150Ryd and 5,5,5 respectively. the optimization setting is the defeult setting. is it correct? what is your recommendation for the setting of scripter?

Thank you

4
General Questions and Answers / optimization of bilayer ZGNR (DFT & DFTB)
« on: November 21, 2015, 13:26 »
Hello

I use ATK 2013 and i'm trying to optimize a billayer ZGNR. i've used DFT and DFTB methods and in both cases the result of optimization is something like the attached picture (http://8pic.ir/images/f6x8dz50sqxwos2oq2d3.png). The mesh cut-off and k-point sampling are set to 150Ryd and (5, 5, 5) respectively. Could u please tell me why the optimized bilayer structure is somehow bended? Is there any problem? If yes, What is the solution?

Thank you

5
General Questions and Answers / local electric current distribution
« on: November 16, 2015, 11:16 »
Hello

I use ATK2013. I have attached a figure for u via this link (http://s6.uplod.ir/i/00705/fj4rfzagkuca.png).
I would like to know that is it possible to obtain "local electric current distribution" for GNR like the attached figure (by ATK2013)?

Thanks

6
General Questions and Answers / using 2014 parameters in 2013
« on: October 14, 2015, 12:33 »
hello

I use ATK 2013. I would like to know that is it possible to download parameters which are added to 2014 (like Bassani...), and using them in 2013?

thank u

7
General Questions and Answers / "eigenstate" and "transmission eigenstate"
« on: November 30, 2014, 14:11 »
Hello

I would like to calculate MPSH. could you please let me know about the parameterization of "eigenstate" and "transmission eigenstate"? i mean quantum number, k-points and ...? is there any tutorial about this concept?

Regards
 

8
General Questions and Answers / HOMO LOMO (MPSH)
« on: November 30, 2014, 12:54 »
Hello

I'll be thankful if you let me know that how can i find the MPSH states of the HOMO and LOMO in the central scattering part of the strained (tensil and compressive) 10AGNR? In general I need some information about plotting MPSH states of LOMO and HOMO

Regards

9
General Questions and Answers / how to find the Bg of left/right electrods of a biased device (7-AGNR device) ?
« on: October 6, 2014, 18:30 »
hi

we set out to work on a 7-AGNR device by ATK 2013, could you possibly let us know that how can we find the bandstructure (in other words the Band gap) of the left/right electrodes individually while we applied a bias voltage (2V)?

thanks

10
General Questions and Answers / rectangular SiNW
« on: September 24, 2014, 01:12 »
Hello

I work on SiNWFETs by ATK 2013.
Could you possibly tell me that how can I creat a rectangular SiNW grown in <110> direction?
The confinement directions are <001> and <1 -1 0>  . 
The actual dimensions is 21.27Å*20.35Å and equivalently (m=16atom*n=12atom), where m and n denote the number of atoms in the <001> and <1 -1 0> directions respectively.

I have used builder => NW to creat a 2nm*2nm 110 NW, but I do not know how should I determine the surface energies. I have tried random numbers too ,but I could not achieve the rectangular shape. so I have decided to use the builder => surface(cleave...). it has 3 steps. Could you please give us a description about the parameterization? I would like to know that how should I change them in order to reach to the aforementioned structure?

I would appreciate a reply at your earliest convenience.
Regards

11
General Questions and Answers / source/drain dopping
« on: September 17, 2014, 18:16 »
hi

The donor density in the source and drain regions of a SiNW FET is 1.0*10^20 cm^-3. Could you please tell me that how can I define this dopping?
I've checked    http://quantumwise.com/forum/index.php?topic=3024.0#.VBmyDpSSzDQ    but i didn't understand that where should i add the code exactly? do you mean after

# ---------------------------------------
# left electrode
# ---------------------------------------

and

# ---------------------------------------
#right electrode
# ---------------------------------------

respectively?


Thank you very much for your help and support

12
General Questions and Answers / GAA SiNW FET
« on: September 16, 2014, 21:14 »
Hi

I'm trying to simulate a SiNWFET by ATK 2013.
The NW is rectangular (W=2). When I creat the gate and dielectric, the NW does not locate at the center of the gate (as you see in http://8pic.ir/images/0htkkavckknuh94oy5gk.png ).
How can I move the NW to the centeral point of the gate? Another question is that how can I creat the Source and Drain regions?

Thanks

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