Dear Kwant Developers, I am a graduate student learning Kwant for my academics project related purposes. With reference to the Kwant 1.3.1 Documentation (vide page no.45), the honeycomb lattice for the zig-zag edged graphene has been defined as:

graphene = kwant.lattice.general([(1, 0), (sin_30, cos_30)], [(0, 0), (0, 1 / sqrt(3))])

where, as per my understanding, the first argument to the *general* function is the list of *primitive vectors* of the lattice; the second one is the *coordinates of basis atoms*. According to the physics of graphene, the carbon-carbon bond length is approximately 0.142 nm. But after running the above code, I checked that the C-C bond length of the honeycomb lattice is coming as 1/sqrt(3) nm i.e. ~0.58 nm. Therefore, I am feeling quite confused as I am failing to understand where I am going wrong or whether am overlooking any fundamental concepts. I had also raised my query earlier here, regarding defining the lattice for armchair edged graphene (vide Volume 59, Issue 6), but it seems that unfortunately it has missed your notice. So my understandings on this specific domain are still quite hazy. It would be of great help if you look into the matter and kindly guide me to find solution for the above mentioned queries. Thanks Regards Arunabha Ghoshal