QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Roc on February 14, 2009, 08:01

Title: some questions about the electrode
Post by: Roc on February 14, 2009, 08:01

Dear everyone,

I try to  produce the electrodes using semi enclosed nanotube or one fullerene like C70, but it seems difficult to get it by VNL because of the periode boundary conditions. Could anybody give me some advice
 to produce these two types of electrode and how to definite the screening layers.
 

thanks,

Title: Re: some questions about the electrode
Post by: Anders Blom on February 16, 2009, 20:26

Generally speaking this is not very difficult. The periodic boundary conditions only apply to the electrode, and so you place the caps in the central region, like so:

Code

===========> ... <=============
     |                 |

where = symbolically means nanotube, < and > are hemispheres and ... is whatever you wish to place in the central region. The vertical lines indicate the boundary between the electrode and the central region.

Does this resemble the kind of geometry you wish to set up?

Now, to do it in practice, all you really need are prepared hemispherical caps (say, as xyz or another molecule file), then you put a nanotube from the Nanotube Grower into the Atomic Manipulator, cleave it, and insert and align the caps.

I can give some more details if needed.

Title: Re: some questions about the electrode
Post by: Roc on February 17, 2009, 11:44

Thank you Anders Blom! It troubles me that  how to produce  the hemispherical caps  and join them with the nanotube electrodes expediently using VNL. Can you  give any advice? thank you very much!

Title: Re: some questions about the electrode
Post by: Anders Blom on February 19, 2009, 17:11

I admit, it is not trivial. Actually, generating coordinates for capped nanotubes is in general very difficult. I'll see if I can cook something up for at least the "usual suspects", (5,5) and (9,0) capped by C60...

Title: Re: some questions about the electrode
Post by: Roc on February 20, 2009, 02:12

Thanks for your attention!