Dear Dr. Papior, Since my system is a slab, so the scattering occurs in two dimensions (the transport direction and also the transverse direction), According to two directions, I think that denser k point sampling along two directions must be used. Am I right?
Thanks in advance, Best regards, Nadia Salami On Sat, Jul 25, 2015 at 11:46 AM, Nick Papior <[email protected]> wrote: > > > 2015-07-25 6:55 GMT+00:00 Nadia Salami <[email protected]>: > >> Dear Transiesta users, >> >> I don’t know how to determine correct k point sampling for the Transiesta >> as well as Tbtrans calculations. >> > You converge using the same principles as standard DFT, for transport > calculations however, you converge the averaged transmission. > >> In details, I have determined k-point sampling for the electrode of my >> system from the energy convergence test, that leads to the following >> sampling >> >> %block kgrid_Monkhorst_Pack >> >> 1 0 0 0.0 >> >> 0 2 0 0.0 >> >> 0 0 4 0.0 >> >> %endblock kgrid_Monkhorst_Pack >> >> >> >> Must the k grid along the transport direction (i.e. kz) be increased to >> simulate the semi-infinite lead (electrode)? >> > I would always use as many k-points in the z-direction as you can (the > more k-points, the better description of the self-energy you get). > I typically use 100, if that proves too much, I try with 50. > >> Moreover I know that, the denser k-point sampling must be used to >> calculate the transmission using Tbtrans utility. Must kx and ky be >> increased? For Tbtrans calculation or both of Transiesta and Tbtrans >> calculations? (Also I know that kz only is utilized to calculate siesta >> calculation in the scattering region.) >> > Transiesta calculates the density, tbtrans calculates the transport. > >> Finally, how to converge the k-point sampling for the transmission >> calculation? >> >> It will be highly appreciated your comments and guidances. >> >> Thanks in advance, >> >> Best regards, >> >> Nadia Salami >> >> >> > > > > -- > Kind regards Nick >
