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
