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 to calculate the transmission. Am I right?
Thanks in advance, Best regards, Nadia Salami On Sun, Jul 26, 2015 at 11:53 AM, Nadia Salami <[email protected]> wrote: > 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 >> > >
