Messages

1

General Questions and Answers / Re: Defects creation in Carbon Nanotubes

« on: September 20, 2009, 06:12 »

Thank you so much for the suggestions.
Is it possible to perform the annealing simulation for CNT with monovacancy defect?

2

General Questions and Answers / Re: Defects creation in Carbon Nanotubes

« on: September 18, 2009, 21:01 »

Thanks a lot. So the defect creation method is correct, right?

3

General Questions and Answers / Defects creation in Carbon Nanotubes

« on: September 18, 2009, 20:31 »

Hi all, I tried to create defects in Carbon Nanotubes. Here is what I did: First, drop the CNT.vnl into Bulk Builder and repeat it in Z-axis. Then select the atoms to delete or replace them by other element.

Please advise me if this is correct or not, and if we have to do the structure optimization after the defects are created. Thank you very much.

4

General Questions and Answers / Re: chemical bond

« on: September 15, 2009, 16:23 »

Can we compute the charge density using ATK/VNL? Thank you.

5

General Questions and Answers / Re: chemical bond

« on: September 13, 2009, 19:53 »

Thank you so much for your help. Is there any criterion that we can claim that a chemical bonding is formed at the interface between A and B atoms?

6

General Questions and Answers / chemical bond

« on: September 12, 2009, 16:31 »

For a two-probe system, after the geometry optimization, how to estimate if a chemical bonding is formed at the interfaces? Thank you very much.

7

General Questions and Answers / Re: From crystalmaker to VNL

« on: August 5, 2009, 00:46 »

Could you give the details how to convert CrystalMaker file into ATK? Thanks a lot.

8

General Questions and Answers / Re: two-probe system optimization

« on: August 5, 2009, 00:35 »

Is there any script available to compute the relation of total energy versus distance in a two-probe system? Thank you very much.

cherry

9

General Questions and Answers / Re: k value on Transmission coefficent

« on: July 28, 2009, 04:50 »

Thanks a lot for the comments.

10

General Questions and Answers / k value on Transmission coefficent

« on: July 27, 2009, 21:07 »

Dear all,

The k value for transmission coefficient calculation is usually taken between -0.5 to 0.5. Anyone can give more details why k is at this value range? Thank you.

Cherry

11

General Questions and Answers / Re: two-probe system optimization

« on: July 17, 2009, 23:35 »

Hi Nordland, thanks a lot. Here is the script for a two-probe system.

12

General Questions and Answers / Re: two-probe system optimization

« on: July 17, 2009, 18:23 »

I did not get the final vnl file since it is not finished yet after hundreds of steps. I plotted the 3-D geometry using matlab, and showing the distortion (one electrode is moving away along x-y plane, assuming z-direction is for current flow.). Does it mean that the optimization methods in ATK are not suitable for two-probe system optimization? Thanks.

13

General Questions and Answers / Re: question on transmission coefficient

« on: July 17, 2009, 18:19 »

Thanks a lot. Nordland

14

General Questions and Answers / two-probe system optimization

« on: July 17, 2009, 16:21 »

Sorry to bring up this topic again.
I tried to optimize a two-probe system using the methods supplied by ATK/VNL. Although the atomic force is getting smaller and smaller, while the geometry is dramatically distorted (which is not supposed to be). It was suggested that calculating the total energy versus the distance is the best way using ATK/VNL. Is that correct?
Thank you.

15

General Questions and Answers / Re: question on transmission coefficient

« on: July 17, 2009, 15:39 »

Thanks a lot, Nordland.
How many waves for a 3-D electrode in a two-probe system? Should we use transmission eigenvalues or eigenstate to estimate it? Thanks.