How can we achieved this in ATK?

[zdhlover]

Hi, everyone

The junction of connections through a charge neutral 5-member ring as below, our calculations yield local spin polarization connected to the nominally unpaired pz electron on the apex C atom. In one article they say that the local spin polarization can be compensated by doping the CNTs. Experimentally, doping could be achieved either chemically with alkali atoms or by applying a back-gate voltage.To simulate this, they dope the junction with two electrons which are then compensated by an equivalent background charge spread uniformly over the whole extended molecule. And they find that doping indeed leads to additional charge around the two apex C atoms which compensates the local spin.

And my question is  how can we achieved that dope the junction with two electrons in ATK?


And I also want to know the meaning and the using method of charge in Basis set parameters of ATK.
Thanks!

[Anders Blom]

Since ATK 2010.xx actually supports the inclusion of a back-gate (cf. the graphene junction device tutorial), I would say that would be the absolutely best approach!

The charge parameter in the basis set has nothing to do with the charge in the system. When constructing the basis set, you can in principle set a different pseudocharge of the core when solving the initial atomic problem in order to determine the basis set. However, the atoms it is used on will still be neutral, the charge setting only influences the shape of the orbital. This could be used is to find a better basis orbital, but it's probably very tricky in practice...

[zdhlover]

Thanks a lot!
And I want to know how can we achieved that dope the junction with two electrons in ATK 2008.10?

And I also want to know how can we compute the Local density of states in the energy window as [-0.5 eV, 0.5 eV] not one energy value in atk 2008.10?