Topics

1

General Questions and Answers / zigzag silicene nanoribbon (ZSiNR) junction

« on: November 27, 2019, 15:30 »

hello all,

I have constructed ZSiNR-biphenyl-ZSiNR junction geometry. But when I optimize it, then it shows an error message. Geometry with script and error message are attached herewith.

Please reply what I did wrong???
how I can get optimized geometry of ZSiNR-biphenyl-ZSiNR junction???

 

2

General Questions and Answers / SET

« on: July 6, 2019, 09:20 »

Hello everyone,

I want to know how to calculate charge state against gate voltage, and charge state against drain voltage plot for single electron transistor model.

Also,  is it possible to calculate transmission spectrum and IV curve for SET model using ATK-VNL.

Please do reply.
Thanks in advance!

3

General Questions and Answers / how to calculate alignment of magnetic moment in electrode in two probe geometry

« on: January 2, 2018, 16:38 »

Hello all,

In two probe geometry how I can calculate the transport dependence on the alignment of magnetic moments in the Ni electrodes?

Please help!

Regards,
Sweta

4

General Questions and Answers / properties of perovskite structure

« on: October 5, 2017, 20:23 »

Hello everryone,

I want to know what properties of perovskite structure can be calculated using ATK-VNL? Can we calculate structural, electronic, optical properties like refractive index, dielectric constant for perovskite structure using ATK-VNL?

Thanks!
Regards,
Sweta

5

General Questions and Answers / spin transport study in two probe geometry

« on: September 24, 2017, 07:20 »

Hello everyone,

In two probe geometry, I have used a molecule sandwiched between  Ni electrodes for the calculation of transport properties. Now I want to analyze the spin effect on DOS.
How is it possible? What parameter I have to change for molecule, anchoring groups and electrodes?

6

General Questions and Answers / perovskite CH3NH3PbI3 study througk ATK-VNL

« on: February 2, 2017, 07:03 »

Hello all,

I want to build perovskite CH3NH3PbI3 structure and study its  band structure througk ATK-VNL. Is that possible??? If yes, then please explain or send me the useful link regarding the same.

Thanks
Sweta

7

General Questions and Answers / asymmetric molecular junctions

« on: May 20, 2016, 12:27 »

Hello all,

I am working on asymmetric molecular junctions. I want to take left side electrode of some metal Au (say), a molecule in the middle connecting to the electrodes through some anchoring group. I want to know what are the possibilities of taking right side electrode.
Can we build junction by taking right electrode like graphene, nanotube, Au/Ag interface etc.  Please suggest me the possibilities of asymmetric junction that use two different type of electrodes which can be build in ATK-VNL.

Thanks in advance!

8

General Questions and Answers / Are LDA and SZP appropriate for two probe calculations??

« on: June 4, 2014, 10:48 »

Hi ATK-VNL team,

I HAVE 2 QUESTIONS:
(1)In two probe calculations, we generally use localized basis sets such as Single, or double, plus polarization. But according to  Stange et al. J. Chem. Phys. 128, 114714 (2008), the convergence of transport properties using localized could be problematic. I want to know the reliability of our calculated results???

(2)Also we use LDA to calculate HOMO-LUMO gap in two probe calculations (for eg. Wang et al. Phys. Lett. A 374, 4876 (2010)). But according to T. Rangel el al. Phys. Rev. B 84, 045426, this approximation strongly underestimate the HOMO-LUMO gap. So again the use of LDA is reliable for our calculation?
 

Thanks!!!

9

General Questions and Answers / how to calculate orbital isosurfaces in two probe system

« on: May 6, 2014, 10:08 »

hello quantumwise team,

I want to know how we can do orbital isosurface study of two probe system using ATK-VNL.

Kindly help!
 

10

General Questions and Answers / whether the shape of electrodes effects transport properties of two probe system

« on: April 21, 2014, 08:16 »

Hello all,

In the ATK tutorial of molecular devices dithiol benzene (DTB) molecule contact with two gold (111) surfaces. Also in other articles like
Z.Y. Li, D. S. Kosov, J. Phys. Chem B 110 (2006) 19116-19120, thiol group attached gold (111) surface.

I want to know whether the shape of electrodes influences the transport behavior of the devices. If yes, then why (111) surfaces is always preferable than other electrode shapes?
Kindly help!!

Thanks & Regards,
Sweta

11

General Questions and Answers / doubt in relaxing the geometry

« on: February 6, 2014, 12:12 »

Hello quantumwise team,

In two probe system, when i tried to make Au electrode supercell from fcc structure, i got minima at 2.88 A. When i use the electrode with 2.88 inter atomic distance, at the end of relaxation, i get Au-Au distance between 2.68 to 2.80. Au-Au distance is not same for atoms. Is it possible or i m doing some mistakes in taking parameters to make the geometry??? How we can check feasibility of my system???

Kindly help!!!

12

General Questions and Answers / effect of temperature in two probe system

« on: September 11, 2013, 07:33 »

Hi everyone,

In two probe system, can we measure the effect of temperature (of device) on current through ATK. If yes, then how?

Thanks!!

13

General Questions and Answers / force required to break S-Cu bond

« on: June 21, 2013, 08:50 »

Hi,

As we know the value of force required to break S-Au bond is about 1.5nN in molecular junctions. Likewise what is the value of force required to break S-Cu bond?

14

General Questions and Answers / how we can calculate streching distance dependence using ATK

« on: May 30, 2013, 10:24 »

Dear all,

I have gone through the paper entitled "conductance of streching oligothiophene single-molecule junctions: A first-principles study", J. Physical Chem C, 115, 25105 (2011).


During streching, I have also calculated the distance between Au-S bond on sandwitching biphenyl dithiol molecule between two Au(111)-(3*3) electrodes. Then reoptimize the structure. But after aptization the breaking distance between Au-S bond that I have calculated is much smaller (~2) than reported value (2.36). Why this difference occurs? How i can calculate streching effect correctly?

15

General Questions and Answers / study of asymmetric electrode materials

« on: May 10, 2013, 09:25 »

Hello everyone,

I want to study the asymmetric electrodes in two probe system. The problem is that when we change right electrode material by editing script in editor and send to builder, it will convert into bulk rather device mode. How i can convert into proper device mode to study the junction system???

Thanks in advance!