I am struggling with getting a correct band structure for even pristine graphene using SIESTA. The issue is almost certainly the K point path. My graphene sheet (128C atoms) isn't the traditional hexagonal cell. Here it is written in the ".fdf' style of siesta :
LatticeConstant 19.7473282 Ang %block LatticeVectors 1.0000000 0.0000000 0.0000000 0.5000000 0.8666666 0.0000000 0.0000000 0.0000000 2.0255851 %endblock LatticeVectors
And here is the Path I'm using
BandLinesScale pi/a %block BandLines 1 0.0000 0.0000 0.0000 /Gamma 30 1.1547005 0.0000 0.0000 M 30 1.1547005 0.6667 0.0000 K 30 0.0000 0.0000 0.0000 /Gamma %endblock BandLines
Can anyone help me determine the proper k point path with the correct high symmetry points for this type of structure just to at least be able to reproduce the graphene band structure we observe in literature ?
Let me just add that I've tried : More kpoints, better convergence criteria, different functionals and most other obvious solutions but I still can't get the proper band structure