[DFTB-Plus-User] Kpoints

[Mat Toliday]

Dear Toufik,

DFTB+ is sensitive to k-points. It looks like you need less than 12 k-points for the energy to be converged for your system but it will depend on the dimensionality of your system and how you position the k-points. However, if you have a large supercell then the number of k-points required will be lower (same as with DFT). Try using a single k-point and seeing if there is a difference in energy. 
Mat






On Monday, 23 March 2020, 10:07:06 CET, toufik esssakhri via DFTB-Plus-User <dftb-plus-user at mailman.zfn.uni-bremen.de> wrote: 





  

Dear all, 





why DFTB+ is not sensitive to Kpoints?

I have modified the kpoint from 12 to 48 but I got the same total energy!




12 -331.0231

14 -331.0231


16 -331.0231


18 -331.0231


20 -331.0231


22 -331.0231


24 -331.0231


26 -331.0231


28 -331.0231


30 -331.0231


32 -331.0231


34 -331.0231


36 -331.0231


38 -331.0231


40 -331.0231


42 -331.0231


44 -331.0231


46 -331.0231


48 -331.0231






Sincerely



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