Dear all, I am a new user of Siesta. I am working on graphene and Zigzag Carbon nanotubes. I have encountered a serious problem with defining k-grid cutoff in my jobs. Here is a part of my input:
kgrid cutoff 15.003 Ang But I have this in my output file: siesta: k-grid: Number of k-points = 1 siesta: k-grid: Cutoff (effective) = 2.460 Ang siesta: k-grid: Supercell and displacements siesta: k-grid: 0 1 0 0.000 siesta: k-grid: 1 0 0 0.000 siesta: k-grid: 0 0 1 0.000 Naive supercell factors: 4 4 1 Which gives 2.46 Ang cutoff an just gamma point!!! I tried the kgrid_Monkhorst_Pack with 31X31X1 grid for graphene, but from the outputs I can say that the effective k-grid cutoff is totally independent of the mesh grid I've defined in my input and it just changes by changing the length of the vector in Z direction (which is perpendicular to the graphene plane) in my unit cell. Could anybody guide me why I get these weird outputs?! Thanks in advance, Elham Beheshti, Department of Electrical Engineering, University of British Columbia
