Hi, <br>Recently I have started using xcrysden and have some questions
regarding the K-point selection. I have considered a graphene structure
with two carbon atoms in the unit cell. From the K-path selection, I can
see the primitive brillouin zone is hexagonal in structure and I can
directly read coordinates of the symmetric points viz. Gamma, M and K in
the reciprocal lattice. But when I increase the number of carbon atoms
in the unit cell say four atoms or eight stoms, the primitive brillouin
zone comes out not to be hexagonal but rectangular in shape which is
wrong. I have checked my structure, there is nothing wrong with it and
it is indeed graphene. I also tried by changing the shape and angle of
crystall cell but all the time the primitive brillouin zone comes out
rectangular. I am trying to find the bandstructure of graphene and other
graphenelike structures but unable to proceed. Please help <br>
<br>Thanks in advance<br>