Dear all, I have been trying to understand the sampling of the Brillouin Zone for integration in the k-space. The method adopted in the automatic generation scheme in Espresso is the Monkhorst-Pack one. I have been reading the file kpoints.f90 in
espresso-5.0/PW/tools/ and I went through some of the forum archives http://www.democritos.it/pipermail/pw_forum/2012-February/023321.html to understand this. I think the algorithm follows these lines 1. generate a shifted uniform grid in *crystal space* of *the reciprocal lattice* and associating a weight of 1/(total no: of k points) 2. use symmetry of the reciprocal lattice to reduce the list Here the weights of the eliminated points are accumulated on to the remaining ones This is what I was hoping to find a) Some sort of check that ensures that k points fall within the Wigner-Seitz Cell (first Brillouin Zone). b) During the generation of the k point mesh, the sampling seems to not extend in all quadrants of the crystal space, i.e., I am not able to find negative crystal vectors. I expect them because the Brillouin zone extends in all quadrants. Can someone please explain this to me? Regards Meenakshi Sundaram M Grad Student Mechanical and Aerospace Engineering Ithaca Cornell -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120629/1e2ca68b/attachment.htm