Dear kwant users,
Hello everyone, while using Kwant, I noticed that in the tutorials, a square
lattice (a=1) is used for building structures. However, in the graphene
tutorial, 'kwant.lattice.general' is used, with the following code:
--------------
graphene = kwant.lattice.general([[1, 0], [1/2, np.sqrt(3)/2]], # lattice
vectors
[[0, 0], [0, 1/np.sqrt(3)]]) # Coordinates of
the sites
a, b = graphene.sublattices
---------------
Attached is the image of the graphene lattice.
I have found the method for using kwant.lattice.general:
kwant.lattice.general(prim_vecs, basis=None, name='', norbs=None)
But when it comes to the mentioned graphene, I cannot understand the usage of
'’kwant.lattice.general’'
The code mentions that the lattice vectors are ‘'[1, 0], [1/2, np.sqrt(3)/2]’',
which appears to be a parallelogram. I assume it corresponds to a unit cell.
However, the code mentions '’[[0, 0], [0, 1/np.sqrt(3)]]'’ as ‘'Coordinates of
the sites'’, and I don't understand which two atoms it corresponds to. Can any
scholar help me resolve my doubts?
My second question is, when using Kwant, do I need to input the lattice
constant? If so, where should it be written?
Best wishes.
Sincerely,
Araya
