Dear Andrei, Sorry for my misunderstanding of the results. You are right. I increased the sampling points in the y direction from 17 to 100. That is, I used the following block for tbtrans calculations:
%block kgrid_Monkhorst_Pack 1 0 0 0.0 0 100 0 0.0 0 0 15 0.0 %endblock Kgrid_Monkhorst_Pack The resulting transmission is attached as "1X100X15.ps". As far as I know, the density of states of graphene sheet falls to zero at the K point band crossing. Moreover, the band crossing coincides with the Fermi energy which is equal to zero eV in our case. Hence, the transmission must touch zero only at 0 eV. Comparing "1X100X15.ps" with the "1X17X15.ps" attached previously, it is evident that by increasing the number of sampling points in the y direction, the transmission at the zero eV approaches towards zero. Thank you again for your help Andrei. Best wishes, Mohammad
1X100X15.ps
Description: PostScript document
