Dear Joe I am a freshman about Kwant and I want to use Kwant exactly.I will try to define the lattice differently as you adviced.Aha,thank you for your response and it's really happy to communicate with you. Thank you again. Bill - 2018-04-26 17:26 GMT+08:00 Joseph Weston :

Hi Bill,

Dear Joe "add_site_family" did work in graphene zigzag nanoribbon.When I use "add_site_family",the central scattering region would not enlarge after connected with leads in zigzag nanoribbon.But when I use it in graphene armchair nanoribbon,the central scattering region will enlarge. If you have spare time,you can run my code,and you can see the picture that the central scattering is enlarge a little in up and downd leads,left and right lead is right. Thank you Bill Yang

Ah, I understand now. In your original email you talked about a "triangle of sites", which I did not see in the images you posted, so I was unsure what you were talking about.

I don't think you be able to get rid of the "extra added bit" with a judicious choice of 'other_vectors'; I think you'll have to define the lattice differently in order to do what you want.

On the other hand, is this extra added region such a problem? There will be no physical consequences, as the extra added piece has the same Hamiltonian as the leads...

Happy Kwanting,

Joe