Dear Zhang, I see two problems in your code: you have a problem with indentation: syst is defined inside the function onsite_CTSC! make a back indentation to get it to the right place. your shape function contains a condition on x solely. Put limits on y too. correct these mistakes and then check carefully your program. I hope this helps Adel On Wed, Jan 23, 2019 at 11:11 AM 张金龙 <jlzhang1996@163.com> wrote:

Dear Colleagues,

I want to build a structure as shown in picture. There are 5 parts.

I want to construct it by define the shape function shown in TUTORIAL: *Nontrivial shapes*. However, when I want to attach a 1D lead on the two-side, I get a message: ValueError: Sites with site families (kwant.lattice.Monatomic([[1.0, 0.0], [0.0, 1.0]], [0.0, 0.0], '', 4),) do not appear in the system, hence the system does not interrupt the lead.

Can you give me some hints?

Maybe my description is not clear, I attach the code in the e-mail to reproduce this question.

Best wishes. Jinlong Zhang jlzhang1996@163.com

-- Abbout Adel