How to set the mesh grid cutoff

[Luis M. Villamagua C.]

Hi guys,

Can someone explains to me what Grid Mesh cutoff is for?? VNL is giving me default values. I do not know if I should Increase or decrease it value? Or should I optimize it the same way I optimize the k-point? Does it depends on the number of atoms my nanoribbon has??

Thanks in advance for your help.

Regards,
Luis

[luca]

Your mesh grid cutoff is an energy cutoff which corresponds to the fineness of the real space grid.
It should be the value for which your results converge generally!
Or to say it in another way you have to increase it till convergence is reached but it also depends in some cases on which properties you wanna calculate.

It does NOT depend on the number of the atoms generally, more atoms mean rather an increase in the computation time.

Bests