How to adding electric field in nanoribbons

[coollailai]

Hi
First, in ATK, There is a Boxregion object which can creat electric field in the nanospace. If I want to add an electric field on the nanoribbon model, I just need to write those language? And where are those words placed in the whole text?
 'metallic_region1 = BoxRegion(
        1*Volt,
        xmin = 0*Angstrom, xmax = 41.439*Angstrom,
        ymin = 0*Angstrom, ymax = 0.5*Angstrom,
        zmin = 5*Angstrom, zmax = 15.*Angstrom
        )

metallic_region2 = metallic_region1(
        value = -1*Volt,
        ymin = 10*Angstrom, ymax = 12*Angstrom
        )
'

Second, is there a method to add electric field whose direction is equal to the axis of nanoribbons? Axis of nanoribbons is usually the Z-axis in the model.

I hope you can give me some helps~~~

[zh]

The "Boxregion" mentioned by you is available for the gate bias voltage, not for an external electric field.  

[Nordland]

If you have more than one metallic box region with different gate biases, you will create a electric field between the two gates.
If you are not experience with programming I can recommend using the builder to add these metallic regions.

[coollailai]

The "Boxregion" mentioned by you is available for the gate bias voltage, not for an external electric field.  

Is there a method to adding external electric field?

[zh]

It seems that the current version of ATK does not support the the functionality of applying external electric field. You may try other softwares such as abinit and quantum-espresso.

[Nordland]

It is possible to get the exact same effect as external electric field. You just have to setup it using metallic regions.

Here I have attached a system of graphene ribbon with a two metallic regions which will give an electric field strength of 0.1 V/Å.

[coollailai]

It is possible to get the exact same effect as external electric field. You just have to setup it using metallic regions.

Here I have attached a system of graphene ribbon with a two metallic regions which will give an electric field strength of 0.1 V/Å.

I tried your advice and it works! thx~