Messages

1

General Questions and Answers / Re: Calculation the bandstructure of bilayer AGNR with relative motion

« on: October 16, 2014, 02:16 »

thanks a lot for your answer.
i know this structure is not periodic in Z direction but whether it means there is not any band gap in this structure? if there is a band gap in this structure, how can i get the band gap?
1- can i turn the device into bulk and get it's band gap ?
2-can i get the band gap through the transmission spectrum ?
3-are you sure Slater-Koster method is not proper for this structure? what about Extended Huckle?

thank you for your help.

2

General Questions and Answers / Re: Calculating Conductance, Resistance in two-probe system

« on: October 15, 2014, 21:22 »

Hi
 results are exactly the same whether you calculate the conductance using conductance custom analyzer or  I/V. see the results again. you are probably making a mistake. unit of conductance should be the same in both cases. for example SI unit.

3

General Questions and Answers / Re: About k point sampling

« on: October 13, 2014, 15:27 »

you need only 1×1×100 k-points to calculate the bandstructure of graphene nanoribbon (GNR). the system is finite in x and y directions so 1×1 k-points seem to be sufficient in these directions while it is periodic in z direction so 100 k-points can be suitable.

4

General Questions and Answers / Calculation the bandstructure of bilayer AGNR with relative motion

« on: October 9, 2014, 12:31 »

Hi

 i'm a moderate user of ATK and have no problem with mono-layer GNR  but i have made a bilayer AGNR configuration with relative sliding motion as shown in the images. i want to turn it into device and calculate the transmission spectrum, but before turning it into device, i want to obtain the bandstructure of the configuration.  i'm using Slater-Koster method (ATK-13.8.1). could you please tell me:

1- how many k-point samples i should insert in a , b and c directions?

2- which basis set is prefered? there are only three options , Hobbit ,CP2k selfconsistent and CP2k non-selfconsistent.

3- what boundary conditions should be selected for poisson solver? are the default conditions suitable?
 
i'm looking forward to your answers.
very thank.

5

General Questions and Answers / strain on CNT

« on: October 3, 2014, 22:54 »

for uniaxial strain on CNT we can change the lattice parameter in Z or C direction when fractional coordinates constant is kept.for example assume the C parameter is 1nm. when we change it to 1.1nm, it means we have applied 10%  tensile strain on CNT. for 10% compressive strain, the C parameter should be changed to 0.9nm. is it correct?